Mechanical Application and Installation Guide for the CX35 On-Highway Transmission{1400, 1408, 3030, 3101} Caterpillar

On-Highway Transmission:

CX35 (S/N: W3X1-UP)

Introduction

This document is a basic reference and a guide for the application and installation of Caterpillar Transmissions for on-highway use. The primary purpose of this document is to assist engineers and designers specializing in the application and installation of the CX35 On-Highway Transmission. This document covers the mechanical portion of the CX35 transmission while the Special Instruction, REHS2791, "Application and Installation Guide (Electrical) for the CX35 On-Highway Transmission" covers the electrical portion of the transmission.

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NOTICE
The mechanical and electrical Application and Installation Guides are stored and printed from an electronic file. These files may be revised periodically. To ensure that your hard copy of the Special Instructions is the current version of the Application and Installation Guide, consult your local Caterpillar Representative. All paper copies are uncontrolled. Caterpillar reserves the right to update, improve, and or change the design of the CX35 Transmissions. Due to continuous design and product development updates, the information contained herein is subject to change without notification.

References

• Special Instruction, REHS2884, "Application and Installation Guide (Electrical)"

• Operation and Maintenance Manual, SEBU8203, " CX35 Transmission"

• Disassembly and Assembly, KENR6060, "CX35 Transmission"

• Systems Operation, Troubleshooting, Testing and Adjusting, KENR5099, "CX35 Transmission"

• Specifications, Systems Operation, Testing and Adjusting, KENR5256, "CX35 Transmission"

CX35 Technical Review

Caterpillar transmissions are designed and built to provide superior value. However, achieving the value expectations of the end user greatly depends on the performance of the various components and systems of the entire power train. The transmission is only one part.

During the initial stages of the OEM's application request, the engine and transmission ratings must be evaluated. See the transmission ratings table that is in the ""Appendix" " for technical data. Contact the application engineer for additional duty cycle information and the current ratings for your transmission application.

In order to validate the performance of the transmission and better ensure end-user satisfaction, Caterpillar requires a mandatory technical review of the initial transmission installation for the OEM as a prerequisite for the sale of the transmission on an ongoing basis. In addition, a review is necessary whenever a change which might affect the overall performance of the transmission is made to the installation. The OEM is responsible for informing Caterpillar when such a change is made.

This review is performed by OEM personnel at the facility of the OEM with the assistance of qualified Caterpillar technicians. Particular attention is given to the following: cooling, electrical systems, mounting, mechanical drives, serviceability, operator safety and operating environment. A copy of Caterpillar's Installation Review Report with any recommended improvements to the installation will be provided to the OEM. The review report documents the important features and details of the transmission installation and designates those characteristics in the following categories:

• Satisfactory

• Marginally satisfactory

• Likely to lead to user dissatisfaction

• Unsatisfactory

Caterpillar exercises all reasonable effort to ensure that transmissions perform properly in the equipment of the OEM. The responsibility for the transmission installation is that of the OEM. Caterpillar assumes no responsibility for deficiencies in the transmission installation.

Note: The installer is responsible for considering and avoiding hazardous conditions which could develop from the systems involved in the specific transmission installation. The suggestions provided in this guide regarding avoidance of hazardous conditions apply to all applications. These conditions are of a general nature since only the installer is familiar with the details of the installation. The suggestions provided in this guide should be considered general examples and are in no way intended to cover every possible hazard in every installation.

Nomenclature

The CX35 nomenclature covers a broad range of transmission products with the same clutch sizes. Therefore, the owners, users, and service personnel using the correct CX35 arrangement numbers becomes very important. All CX35 transmissions have the same serial number prefix W3X but there are various options within the five serial numbers that follow. Options include but are not limited to the following: converters, retarders, PTO's, sumps, filters, yokes and flex plates. The Caterpillar Dealer will need the prefix and all of the serial numbers to identify a particular transmission.

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External Transmission Features and Identification

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Illustration 1	g01362266
(1) Filter inlet pressure coupler (S·O·S port) (2) Filter outlet pressure coupler (3) Three M16x2 threaded lifting points. The two rear M16 bolts provide a location for a vehicle transmission support. (4) Torque converter output speed sensor (5) Conventional ten bolt PTO at 1:00 o'clock position (6) SAE J615 mounting pads SAE #1 bolt pattern with 6 M16 x 2 threaded holes. SAE #2 width between mounting pads (7) Oil filler and dipstick location (8) Shallow sump oil pan shown 80 mm (3.2 inch) deep. Not displayed standard sump 125 mm (4.9 inch) deep. Not displayed retarder sump 140 mm (5.5 inch) deep. (9) Four M16x2 threaded mounts (10) Transmission output speed sensor (11) Option 1360 N·m (1000 lb ft) rear PTO capability. Specifications in PTO section (12) Rear magnetic drain plug (SAE J1926 #12 port) (13) SAE J1926 #4 auxiliary PTO lube port (14) Output yoke (two options) (15) Transmission mounted cartridge type oil filter

Transmission Dry Weights

CX35 without retarder ... 602 kg (1326 lb)

CX35 with retarder ... 670 kg (1476 lb)

Note: Does not include crankshaft adapter, flex plates, starter ring gear, bolts, output yoke, and ECU. (29 kg (64 lb))

Illustration 2	g01289598
(16) Crankshaft to flex plate adapter (17) Flex plates (18) Engine starter ring gear (19) No. 1 SAE J617 flywheel housing for 12 and 24 bolt mounts (20) Engine output speed sensor (21) Transmission breather and filter (22) OEM electrical interface for 24 and 70 pin connectors (23) Electronic Control Module (ECM) (24) Transmission oil temperature sensor (25) Solenoid protective shield (26) Solenoids clutch controls (six) (27) SAE J1926 #4 auxiliary PTO lube at clutch pressure port (28) Conventional ten bolt PTO at 8:00 o'clock position (29) SAE J1926 #16 inlet from cooler port (30) Lube pressure coupler (cooler outlet) (31) SAE J1926 #16 outlet to cooler port (32) Converter outlet pressure coupler (33) Cooler inlet pressure coupler (34) Converter outlet temperature sensor (35) Converter outlet relief pressure (36) Transmission main relief pressure (37) Filter bypass relief pressure

Center of Gravity

Reference plate: Centerline of crankshaft and rear surface of flywheel housing

Table 1

Standard Sump No Retarder	Shallow Sump No Retarder	Standard Sump With Retarder
X = −3.2 mm (−0.12 inch) Y = −37.5 mm (−1.47 inch) Z = −507 mm (−20.0 inch)	X = −4.15 mm (−0.16 inch) Y = −40.3 mm (−1.59 inch) Z = −507 mm (−20.0 inch)	X = −1.37 mm (−0.05 inch) Y = −48.3 mm (−1.9 inch) Z = −493 mm (−19.4 inch)

Altitude Restrictions

Note: There are no restrictions based on altitude.

Illustration 3	g01359211
(38) Lockup clutch pressure coupler (39) Clutch #1 (C1) pressure coupler (40) C2 pressure coupler (41) C3 pressure coupler (42) C4 pressure coupler (43) C5 pressure coupler (44) C6 pressure coupler (45) Optional rear PTO w/o cover (46) Six base supports (47) Three M8x1 bolts (48) Magnetic filter access cover (49) Oil level sensor connector (Hidden) (50) Converter inlet pressure coupler (51) Sump heater SAE J1928 #16 port (52) Filter bypass switch

Lifting

• Acceptable lift points for CX35 Transmissions include the side and rear transmission mounts. The transmission is designed to sit level on the six base supports for the transmission. See Illustration 3. The solenoid protective shield (25) needs to be on the transmission if placing the transmission on base supports to protect against tipping on the side.

• Care must be taken when lifting to avoid damaging the following components that are mounted externally on the transmission: ECM, ECPC valves, solenoids, wire harness and sensors.

Illustration 4	g01362294
(53) Identification and Serial Plate

Illustration 5	g01304779
(54) Retarders add 104 mm (4.09 inch) to the length of the CX35 (55) Retarder activation solenoid (56) Retarder activation pressure coupler (57) SAE J1926 #24 inlet from cooler port (58) SAE J1926 #24 outlet to cooler port (59) Retarder outlet pressure coupler

Note: Caterpillar transmissions are manufactured, assembled, and tested using hydraulic diagnostic couplers. These quick disconnect couplers for checking that system pressures remain on the transmission for the convenience of the owners and service personnel. Unless otherwise stated, all quick disconnect couplers conform to SAE-J1502 standards.

Mass Moments of Inertia and Axis Orientation

Table 2

Inertia at Center of Gravity
Transmission	Ix (kg−m2)	Iy (kg−m2)	Iz (kg−m2)
CX35 Shallow sump	75.77	71.76	21.49
CX35 Standard sump	74.92	71.17	20.87
CX35 Retarder	79.65	73.67	25.54

Illustration 6	g01364418

Transmission Support and Engine Flywheel Bending Moments

Illustration 7 shows a rear transmission support using coil springs.

Illustration 7	g01212736
One Example

When a Caterpillar transmission is mounted to an engine, a bending moment is created that puts stress on the flywheel housing (FWH). The OEM is responsible for ensuring that the transmission is supported in a manner that prevents overloading of the engine/transmission interface.

The rear transmission support must be designed to statically counteract a minimum of 25 percent of the maximum allowable bending moment at the FWH. Illustration 8 shows a typical cantilevered engine and transmission mounting arrangement. The engine specification sheets for the manufacturer provide the OEMs with the bending moment capability for each engine model. Caterpillar specifies the maximum allowable FWH static bending moment in the Truck Engine Data Sheets.

The maximum static bending moment for the transmission must include all the attached PTO equipment, hoses, and line groups that are mounted on the transmission. Illustration 9 depicts PTO mounted pumps and the associated centers of gravity. Table 3 in this manual provides an analysis sheet that summarizes common attachments that may add to the transmission bending moment.

If the rear transmission support is in the form of a spring with a vertical rate considerably lower than the vertical rate of the rear engine support, the effect of the mount is in the proper direction to reduce bending forces on the FWH due to gravity. However, the overall effect may be reduced due to dynamic forces.

The use of supports with a vertical rate higher than the engine rear mount is not recommended. This type of support can cause frame bending deflections that can subject the engine/transmission to structural forces. Another precaution is to design the rear transmission support so that the support provides as little resistance as possible to engine roll. This design helps isolate the engine/transmission structure from vehicle frame torsional loading.

Note: The radial and axial stiffness of the engine and transmission mounts need to have spring rates comparable to the loads.

The design of a cantilevered transmission system mount includes the following elements: strength of the engine FWH, engine and transmission mount stiffness, PTO attachments and transmission static and dynamic loads. The number and location of the mounts and the natural frequency can also be critical. If the OEM mounting arrangement is new, unique, or complex, Caterpillar recommends an FEA of the mounting system.

OEM mounting system with a proven field service record will probably work for the CX Series of Transmissions. The system will work if the vehicle, engine, and transmission have comparable power, weight, and applications. OEMs may consult with the engine and transmission application engineers if the OEMs want additional technical assistance.

Each OEMs installation is unique and will need a unique bending moment calculation. However, by way of example a CX35 mounted on a Caterpillar engine without a retarder or PTO attachments may need 340 kg (750 lb) of rear support with a spring rate of 85 N·m (750 lb in). The CX35 with a retarder and without PTOs attachments may need 386 kg (850 lb) of rear support with a spring rate of 96 N·m (850 lb in).

Note: Rear Transmission supports, similar to the supports shown in Illustration 7, are required on all transmission installations.

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Bending Moments

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Method I - Determination of Flywheel Housing Bending Moment - Cantilevered Transmission

Illustration 8	g01296196

Method I - Determination of Flywheel Housing Bending Moment - Cantilevered PTOs, Pumps, and Lines

Illustration 9	g01304389

The static bending moment calculation shall include all attached PTOs, pumps, and associated unsupported hydraulic lines.

1. Obtain flywheel housing bending moment limitation Mx (See Truck Engine Data Sheet).

2. Determine the total bending moment on the flywheel housing. See Illustrations 8 and 9.

3. Calculate required rear support (F). Illustration 8.

F= Rear support lift (Newtons)

Note: L5 and L6 in Table 3 are on the opposite side of the transmission.

Table 3

	Wt, Weight (N)(mass in kg x 9.81 m/s)		Transmission mounting face to CG (m)		Bending Moment (Nm)
Transmission		X	L1	=
8 o'clock PTO		X	L3	=
8 o'clock Pump		X	L4	=
1 o'clock PTO		X	L5	=
1 o'clock Pump		X	L6	=
Rear PTO		X	L7	=
Rear Pump		X	L8	=
Mx		X	Total Bending Moment

Method II - Determination of Flywheel Housing Bending Moment - with Transmission Side Mounts

Illustration 10	g01228722

Table 4

Symbol	Description	Comment
L1	Front engine mount to engine CG
L2	Engine CG to transmission mount	L6 + L7
L3	Transmission mounting surface to transmission CG
L4	Transmission CG to rear support
L6	Transmission mounting surface to the center of the mount.	CX35 = .1218 m (See installation dimensions drawing)
L7	Engine CG to flywheel housing
Ew	Engine weight (N)	(Engine mass (kg) x 9.81)

Table 5

Symbol	Description	Comment
F	Rear Support (N)
Mte	Total bending moment of transmission and attached PTOs	Sum of applicable bending Moments in table
Rw	Total weight of transmission and attached PTOs	Sum of applicable weights
TM	Transmission mount reaction
Tw	Transmission weight (N)	(Transmission mass (kg) x 9.81)
M	Flywheel Housing Bending Moment	Compare to specified limits (1)

( 1 )

Note: Allowable static flywheel housing bending moments are given for each engine in the Truck Engines Performance Manual. See the particular engines data sheet section on mounting systems.

Method II - Determination of Flywheel Housing Bending Moment - with Transmission PTOs, Pumps, and Lines

Illustration 11	g01229701

1. Obtain engine and transmission dimensions, CG, and weight data. Obtain data for PTOs and pumps if applicable.

2. Calculate the transmission bending moment (must include any attached PTOs and pumps). Sum the weight column and the bending moment column to determine Rw and Mte respectively.

3. Calculate transmission mount reaction.

   TM = Rw + (Ew * L1 + Mte) / (L1 + L2) (Newtons)

4. Calculate Flywheel Housing Bending Moment.

   M = Mte + (Rw * L6) – (TM * L6) (Newton meters)

Method II - Transmission Side Mounts

The mounting pads on the side of the transmission converter housing can be utilized to support the rear of the engine. Using this mount configuration is desirable since the transmission overhung mass may be enough to eliminate the need for a rear transmission support.

Note: The transmission side mounts have an SAE 615 No. 1 bolt location pattern. However, the distance between the mounting pads is an SAE 615 No. 2.

The OEM is responsible for ensuring that the transmission is supported in a manner that prevents the loading on the engine flywheel housing due to the transmission exceeding the maximum allowable bending moment. This shall include any PTOs, pumps, and unsupported hydraulic lines attached to the transmission.

Note: When the calculated bending moment exceeds the data sheet allowable limit, contact your local Caterpillar representative to review the application for approval.

Original Equipment Manufactures (OEMs) have several options and various variables when mounting the engine and the transmission in the vehicle. Options include several types of mounts located in two, three, or four locations. Variables include the following: static loads, torque, dynamic "g" loads, resonant frequencies, frame stiffness and the fatigue limit of the mount.

Caterpillar recommends that OEMs perform a power train component system mounting analysis. Most of the major suppliers of engine and transmission mounts have computer programs that can run a power train mounting system analysis. The analysis will identify a compatible mounting arrangement with stiffness and frequencies that do not over or under load each mount within the power train system.

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Installation Angle

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Illustration 12	g01238238

Installation Angle and Vehicle Slope Capability

The installation angle must be taken into account before the CX35 Transmission is installed. The transmission was designed to operate in a horizontal plane that allows for proper hydraulic functionality of the lube, control, and pressure circuits. Refer to Tables 6, 7, and 8. Also, refer to Illustrations 12 and 13 for specifics.

Transmission Installation Angles

Table 6

Installation Angle in Chassis
Condition	Shallow Sump (deg.)	Standard Sump (deg.)	Retarder Equipped (deg.)
Rear Down	0 to 6.5	0 to 6.5	0 to 6.5
Roll	0	0	0

Engine Forward Applications - Operating Angles

Table 7

Maximum Operation Angle - Degrees (Engine forward applications)
Condition	Shallow Sump (deg.)	Standard Sump (deg.)	Retarder Equipped (deg.)
Uphill	31	31	31
Downhill	24	31	31

Table 8

Maximum Operation Angle - Degrees Roll
Condition	Shallow Sump (deg.)	Standard Sump (deg.)	Retarder Equipped (deg.)
Left/Right roll	16	16	16

Illustration 13	g01238240

Engine Aft Applications - Operating Angles

Uphill and downhill conditions for the engine aft applications are opposite of operating conditions for the engine forward applications. Refer to Tables 9 and 10. Also, refer to Illustration 13 for more information.

Table 9

Maximum Operation Angle - Degrees (Engine aft applications)
Condition	Shallow Sump (deg.)	Standard Sump (deg.)	Retarder Equipped (deg.)
Uphill	24	31	31
Downhill	31	31	31

Table 10

Maximum Operation Angle - Degrees Roll
Condition	Shallow Sump (deg.)	Standard Sump (deg.)	Retarder Equipped (deg.)
Left/Right roll	16	16	16

Ground Clearance

Vehicle installations shall provide adequate ground clearance to prevent the transmission from contacting the ground. The OEM must consider approach and departure angles as well as suspension travel. If the transmission is the lowest installed component or if the transmission is susceptible to obstructions, a protective enclosure, such as a bottom guard, must be fabricated by the OEM.

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CX35 Installations

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The CX35 transmissions may be shipped with the flex plates attached to the converter. Other OEMs upon special request to the engine supplier may receive the CX35 transmissions with the flex plates attached to the Caterpillar engine. In either case, the flex plates must be assembled on the engine crankshaft as a first step in mounting the transmission to the engine.

Bolt Torques

Tightening torques are called out in the Installation Dimensions Drawings. Tightening torques called out in the Installation Dimensions Drawing take precedence over the standard torque values listed in the Appendix.

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NOTICE
If bolts are removed from the CX35 transmission to add mounting brackets, etc. they must be replaced with longer bolts so that thread engagement is maintained. The replacement bolts must be of the same grade and torqued to the required specifications. Thread engagement length and bolt torques are critical on the Aluminum Case and Cover of the CX Transmissions. The bolts selected must have a thread engagement length of twice the bolt diameter. Standard torques on short bolts will strip the threads. The bolts must not be too long because the bolts will bottom out and damage the case.

There are three different mounting arrangements for the CX35 to Caterpillar C13, and C15 engines depending upon the flywheel housings and crankshafts being used. The C13 uses installation dimensional drawings, 290-8222 Flex Plate Gp and 290-8223 Flex Plate Gp . The C15 use the 290-8224 Flex Plate Gp . Refer to the Appendix of this Application and Installation Guide for specific installation parts, torques, and instructions.

Flywheel and Crankshaft Assembly

1. Attach the appropriate crankshaft adapter and flex plates to the engine crankshaft.

2. Apply 9S-3263 Thread Lock Compound to the crankshaft bolts prior to assembly of the adapter and flex plates to the crankshaft.

3. Align the adapter and flex plates to the crankshaft bolt pattern using the two alignment bolts.

4. Do not use washers.

5. Using the proper torque sequence, tighten the appropriate crankshaft bolts to the specification noted on the installation drawing.

6. With a manual bar, verify that the engine rotates freely.

7. Sparingly apply 4C-5598 Anti-Seize to the bore of the crankshaft adapter.

8. Align one of the12 torque converter mounting holes on the flex plate with the assembly access hole in the flywheel housing.

Mounting the Transmission

The center line of the crankshaft and the center line of the transmission must be positioned in the same horizontal plane in order to bolt the two components together.

1. Position a tapped hole on the converter housing so that the tapped hole will align with the assembly access hole on the flywheel housing. A 150 mm (6 in) long 9 mm (.375 in) diameter drill rod placed in the converter tapped hole can be used to index the flywheel flex plate bolt holes with the tapped threads on the converter housing. The drill rod will protrude through the flywheel housing assembly hole and the aligned flex plate hole as the converter pilot enters the bore of the crankshaft adapter.

2. Replace the drill rod with the 1^st flex plate to converter bolt as specified on the dimensional drawing for this engine arrangement.

3. Attach converter housing to flywheel housing. Use 12 or 24 bolts 7/16-14-2A bolts and 8T-5360 Washer (hardened steel). Torque the 7/16-14-2A grade 8 bolts to 70 ± 15 N·m (52 ± 11 lb ft).

4. The 9S-9082 Engine Turning Tool is a convenient device for rotating the engine when installing the additional 11 bolts between the flex plate and the converter housing. The tools gear teeth mate with the starter ring gear in the outer hole of the flywheel housing.

5. Install and torque the 12 bolts in the proper sequence to secure the flex plate to the torque converter.

6. For more installation details refer to the instructions on the dimensional drawings included in the Appendix. Be sure that the drawing applies to the engine being mounted to the CX35 transmission.

7. Attach the side and rear transmission mounts as determined by the Bending Moment analysis described earlier in this Application and Installation Guide.

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Power Train Oil System

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The power train oil schematic shown in Illustrations 14, 15 and 16 provides the nominal pressures and flows within the CX35 power train. The CX35 has different oil schematics based on the oil routing for different gears. Gears first and second converter, second through fifth direct, and sixth through eighth, share the same schematics based on hydraulic logic.

The OEM selection of the oil cooler and the lines routing must be sized so that flows, back pressures, and cooling are adequate for the application. In general, the hoses need to be as short and straight as the installations will allow. The cooler section of this guide provides line routing recommendations.

The transmission fluid is critical to the proper operation of the transmission because the transmission fluid serves many functions such as the following: proper cooling, clutch lockup, bearing protection, torque converter operation and general overall interior oxidation protection. In order to maintain the cleanliness of the fluid, the filter must be changed as recommended.

Fluid Recommendations

The CX Series of on-highway transmissions are designed to operate with ATF fluids that meet Caterpillar AT-1 or Dexron IIIH specifications. Extended oil change intervals, require synthetic oils meeting Caterpillar AT-1 specifications. Caterpillar ATF synthetic oil is available through Caterpillar dealers. Refer to the Operation and Maintenance Manual for oil change intervals based on applications.

Note: Do not use Caterpillar TDO-4 oil in the CX Series of on-highway transmissions.

Note: During a system failure of internal components, the power train generates abrasive debris that circulates throughout the system. The debris can cause the valves, the power train, pumps, and actuators to suffer repeat failures. Thoroughly clean debris from the system after a component failure and replace the transmission oil cooler core in order to prevent repeat failures. Refer to Operation and Maintenance Manual, SEBU6250, "Caterpillar Machine Fluids Recommendations" for information on improving the durability of machine components and for additional fluid information.

Temperature Operating Limits

The maximum allowable transmission oil temperatures for normal (i.e. continuous) and intermittent (i.e. testing) conditions are the following:

Continuous sump ... 93 °C (200 °F)

Continuous converter out ... 121 °C (250 °F)

Intermittent sump ... 121 °C (250 °F)

Intermittent converter out ... 149 °C (300 °F)

Oil Temperature Gauges

If the OEM chooses to use a color-coded converter outlet temperature gauge, the following recommendations apply:

Green - Safe zone is below 121 °C (250 °F)

Yellow - Caution zone is 121 °C (250 °F) - 149 °C (300 °F)

The following requirement applies:

Red - Warning zone above 149 °C (300 °F)

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If the OEM chooses to use a color-coded sump temperature gauge, the following recommendations apply:

Green - Safe zone is below 93 °C (200 °F)

Yellow - Caution zone 93 °C (200 °F) - 121 °C (250 °F)

The following requirement applies:

Red - Warning zone above 121 °C (250 °F)

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NOTICE
Operators may use the Yellow zone on an intermittent basis for a short period. Operation above the Red line for short periods of time can result in damage to the oil and the transmission.

Transmission Oil Volumes

Table 11

Transmission Type	Estimated Initial Fill	Service Refill
CX35 Shallow Sump	53 L (14 US gal)	28 L (7.5 US gal)
CX35 Standard Sump	60 L (16 US gal)	34 L (9 US gal)
CX35 with Retarder	64 L (17 US gal)	34 L (9 US gal)

Note: The estimated initial fill volumes will vary by installation, depending on the volume of the oil cooler and the associated lines group.

Optional Remote Transmission Oil Filter

Table 12

Remote Oil Filter Hoses
Name	Part Number	Caterpillar Specification	Description
Hose	122-6873	1E0716	25.4 mm (1.0 inch) I.D.
Coupling	124-2123	-16 ORFS	Female swivel
Adapter	6V-8635	-16 STOR -16 ORFS	Male-X Male

Remote mounting of both styles of filters (cartridge or canister) in a location selected by the OEM is an option. The filter may also be located to facilitate easier maintenance. For remote filter applications, the OEM is responsible for designing a bracket to secure the filter base vertically above the filter element on the vehicle. See 299-0415 Dimension Drawing .

Transmission Hydraulic Schematic

Illustration 14	g01353204

Illustration 15	g01354433

Illustration 16	g01354826

Additional remote oil filter requirements:

• The hydraulic line used shall have a minimum working pressure rating of 5500 kPa (800 psi) and a temperature rating of −40 °C to 121 °C (−40 °F to 250 °F) or higher.

• All remote mount fittings should use high temperature fluorocarbon rubber (FKM) O-rings also known by the trade name Viton. These O-rings have a Shore A Durometer hardness of 75-90.

• The maximum allowable pressure drop per line due to the line length and the fittings is 34 kPa (5 psi). This pressure drop is measured at high idle and during normal operating temperature 80 to 90 °C (176 to 194 °F) at the filter outlet pressure test port and the PTO lube and clutch pressure test port that is located on the rear of the transmission. Both lines should be the same length.

• The remote mount filter shall be located away from the exhaust.

• The hydraulic line connecting to the remote mount filter shall be properly supported. Minimize bend in the lines.

• Consider service access to the filter during the design of the bracket and the location of the remote mount filter. Clearance is required to replace filters and to access SOS and pressure test ports.

• The recommended position of the remote filter base must orient the spin-on element or the canister vertically under the filter base.

Fill Tube

Illustration 17	g01239202
(X) "FULL" mark (Y) "ADD" mark

Refer to the Installation Dimensions Drawing for details on the recommended fill tube geometry and O-ring seal.

Additional Oil fill tube requirements:

• The fill tube does not require venting.

• The fill tube must be clean and dry prior to installation to prevent moisture and dirt contamination.

• Minimize bends required to route the fill tube to an accessible location.

• The fill tube must be secured to the transmission at the mounting pad and the other end should be secured appropriately by the OEM.

• The fill tube cap must be sealed with elastomeric type seal to prevent moisture and dirt contamination.

Transmission Oil Level - Check

The transmission oil level is checked under the following conditions:

1. The transmission is at operating temperature.

2. The engine is at low idle.

3. The transmission is in Neutral.

4. The vehicle is on level ground.

Breather

The Caterpillar CX35 Transmission comes with an installed breather. The purpose of the breather is to balance pressure inside the transmission that can be created during operation. Special care must be exercised not to plug this filter with any type of material (paint, protectant, etc.), and to avoid damage during installation.

Filter Pressure Test Ports

There are pressure taps located on the inlet and outlet of the transmission filter base. The inlet pressure tap is also a dual purpose scheduled oil sampling (SOS) port (designated by a purple dust cap). Use this port when sampling oil for SOS purposes. In order to prevent damage to the seal in the port and a subsequent leak, use 169-8373 Fluid Sampling Bottle when using the fluid sampling port. See Illustration 1 for pressure test port locations.

Remote Cooler Hoses

Cooler ports are located on the left side near the front of Caterpillar Transmissions. The cooler ports are used for attaching hoses to a remote mounted oil cooler. See Illustration 2 for port locations.

Cooler hoses shall have a temperature rating of -40 °C to 149 °C (-40 °F to 300 °F) and a working pressure rating of at least 2413 kPa (350 psi). All cooler fittings should use high temperature fluorocarbon rubber (FKM) O-rings also known by the trade name Viton. These O-rings have a Shore A Durometer Hardness of 75-90.

Non-Retarder CX35 Transmissions are equipped with SAE #16 straight thread "O" ring cooler ports. The recommended hoses need to have an inside diameter of 22.2 mm (0.87 inch) or greater. The working pressure needs to be 340 kPa (50 psi) or greater. The working temperature needs to be -40 to 121 °C (-40 to 250 °F).

Cooler Oil Lines (W/O Retarder)

Illustration 18	g01321365

Table 13

	Name	Part Number	Caterpillar Specification	Description
1	Elbow	030-7951	-16 STOR -16 JIC	Male 90° Male
2	O-Ring (1)	5P-7701	1E2865A	Viton Rubber
3	Coupling	9X-3830	-16 JIC	Female swivel
4	Coupling	9X-3861	-16 JIC	Female 45°
5	Hose	9X-2377	1E1130	22.2 mm (.875 inch) I.D.

( 1 )

Use 5P-7701 Seal O-Ring with 030-7951 Elbow

Retarder options on the CX35 Transmission are equipped with SAE #24 straight thread "O" ring cooler ports. The recommended hoses need to have an inside diameter of 38.1 mm (1.5 inch) or greater. The working pressure needs to be 340 kPa (50 psi) or greater. The working temperature needs to be −40 to 150 °C (−40 to 300 °F)

Cooler Oil Lines (With Retarder)

Illustration 19	g01322372

Table 14

	Name	Part Number	Caterpillar Specification	Description
1	Hose	9X-2379	1E1130	34.9 mm (1.3740 inch) I.D. (1)
2	Coupling	9X-3832	-24 JIC	Female swivel
3	Elbow	030-7953	-24 STOR -24 JIC	Male 90°
4	Seal O-ring	5P-7816	1E2865A	Viton Rubber
5	Adapter	6K-3461	-24 STOR -24 JIC	Spacer
6	Seal O-ring	5P-7816	1E2865A	Viton Rubber
7	Elbow	5R-8894	-24 FSJIC/MJIC -24 Viton	Male 90°

Additional Data:

Note: For maximum retarder cooler performance, the cooler lines should be as short as practical and minimize the use of 90 degree fittings.

1. For maximum retarder performance 38.1 mm (1.5 inch) I.D. hoses meeting 1E1130 specification [i.e 149 °C (300 °F) are required.

2. An alternative Caterpillar hose that meets the 38.1 mm (1.5 inch) requirement is 1E716 122-6875 Hydraulic Hose . However, the top temperature rating for the 122-6875 Hydraulic Hose is −40 to 135 °C (−40 to 275 °F).

3. A high temperature supplier hose that meets SAE specification 100R1 with a 38.1 mm (1.5 inch) I.D. is an alternative where maximum oil cooler retarder performance is required.

Transmission Oil Heater

The CX35 has an SAE J1926 #16 straight thread "O" ring oil sump heater port located under the converter housing. As a general rule, suppliers recommend 8 to 10 watts per quart of sump oil. Commercial heaters with and without thermostats are available in 150, 300, and 500 watt capacities that are compatible with the CX35 transmission. Caterpillar recommends the use of a transmission oil heater when vehicles must be started and the ambient temperatures are below -30 °C (-20 °F). The maximum depth the heater can be submerged is provided in the installation drawings.

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Transmission Cooling (General Recommendations)

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Automatic transmissions generate heat due to converter slippage, charging pump losses, and friction in rotating components. The transmission fluid absorbs this heat, and an oil cooler is required to dissipate the heat. Keeping the oil cool maintains the oi's lubricating properties, allows the transmission to perform properly, and extends the life of the transmission components.

This section of the Application and Installation Guide discusses transmission cooling requirements and the elements that make up the cooling system. The sizing of the cooler, line, and the fluid requirements are also discussed.

The engine coolant (i.e. antifreeze) and the automatic transmission fluid (i.e. ATF) absorb the heat generated by the engine and transmission. The two fluids carry the heat to a heat exchanger (i.e. radiator or cooler) where the oil or antifreeze can be cooled.

Engine Coolant Requirements

Caterpillar recommends a 1:1 ratio of ethylene glycol to water and the proper anti corrosive additives as a cooling medium for the engines radiator. If the vehicle operates below minus 35 °F, a 60:40 ratio of ethylene glycol to water is recommended. See the Truck Application and Installation Guide for specifics.

Do not use water without the proper cooling additives because water does not provide adequate boiling/freezing protection, and water is corrosive to the engine cooling system.

Requirements for the Cooling Systems

The conditions that dictate the cooling system requirements are the maximum values for the following applications and components:

1. Engine: Maximum horsepower.

2. Ambient Conditions: Highest and coldest temperatures anticipated.

3. Applications: Heaviest loads and steepest grades with the highest rolling resistance.

4. Converter: Manual selections of gear ranges where the lockup clutch is not engaged.

Retarder

1. On-Grade Cycle: Heaviest loads with the longest, steepest slopes requiring the lowest speeds on the grades.

2. Start-Stop Cycle: Heaviest loads with maximum acceleration and a 0.15 g deceleration at the rate of 3 to 6 stops per kilometer (5-10 stops per mile).

Converter Cooling

Caterpillar On-Highway Transmissions have lockup clutches that reduce the heat generated by converters in all gears except first forward and reverse. Under normal operating conditions, the transmission will up-shift and downshift to the proper gear ratio and spend most the operating time in the converter lockup clutch mode. The lockup clutch reduces the converter cooling requirements. If the driver selects the manual mode and locks the transmission in a lower gear, the lockup clutch may be disabled. This mode of operation will result in continuous converter usage where converter slippage will generate higher heat loads. The application, ambient temperatures, horsepower being transmitted, and the length of time in converter drive will dictate transmission cooling requirements. In general, the cooling system must be capable of dissipating a minimum total heat load corresponding to the 80 percent converter efficiency point in first gear. More severe off-highway duty cycles may require a cooling system capable of dissipating up to 25 to 30 percent of the net horsepower being transmitted. An additional cooling requirement is that a stationary vehicle, with the engine idling, must not exceed the recommended transmission oil temperatures on days with high ambient temperatures. The stationary test is conducted for 30 minutes of low engine idle with the transmission in gear. In general, normal on-highway driving will generate a cooling heat load of only 5 percent to 10 percent of net horsepower being transmitted.

Cooling Analysis

Caterpillar recommends analyzing the vehicle power train cooling requirements before the OEM selects a particular CX35 Transmission arrangement. Caterpillar's simulation program is called Motion Power Integrator (MPI). Caterpillar's MPI can simulate the vehicle operating conditions selected by the customer. The MPI program will calculate the cooling requirements so that adequate cooling can be provided in the power train design of the OEM. Converter and transmission losses are included in the MPI. If necessary, contact a Caterpillar Application Engineer for further assistance.

Oil Cooler Selection

The design of the transmission oil cooler circuit is the responsibility of the OEM vehicle group. The circuit must be designed to maintain a continuous sump temperature less than 93 °C (200 °F) on days of high ambient temperatures. The CX35 Transmission does not have a specific oil cooler mounting arrangement. The oil cooler manufacturer needs to supply cooler performance curves showing heat rejection capacity and pressure drop to verify that cooling requirements can be met. The performance curves must be derived from test data (not calculated estimates) to insure adequate cooler system results. OEM's can consult transmission application engineers for questions regarding the cooler system design or cooling system tests.

Exhaust Routing

Engine emission controls increase exhaust temperatures. Therefore, the cooling system and the transmissions exterior, especially the oil sump and all electrical components, need adequate heat protection. If the engine exhaust is routed beside the transmission, Caterpillar recommends that you route the exhaust along the right (i.e. non-solenoid) side of the CX35 power train. Heat shields with adequate air circulation are recommended when exhaust clearance is less than 152 mm (6 inch).

Testing the Cooling System

The vehicle manufacturer is responsible for providing adequate cooling for the power train system. The four basic cooling requirements that automatic transmissions need to meet during routine operations are:

• Converter 80 percent efficiency

• Long-term idling

• Frequent start and stop applications

• Down hill retarding

Calibrated instruments will be required to conduct a power train cooling test. The following instruments and vehicle preparations are recommended:

• Ambient temperature recorder

• Transmission oil sump temperature recorder

• Converter outlet temperature recorder

• Cooler outlet temperature recorder

• Engine rpm recorder

• Ground speed or transmission output speed

• Transmission filter outlet pressure

• Converter outlet pressure

• Lube inlet pressure

Vehicle Preparation For Cooling Test

1. Elevated ambient temperatures for the region where the vehicle is expected to operate are recommended. Maximum ambient temperatures are not required, but the cooling tests should not be run when ambient temperatures are below 20 °C (68 °F). Likewise, the cooling test must not be run in the rain or when abnormal high winds may affect the results.

2. The engine is run at full power without the removal of normal engine parasite devices. (The heaters and the A/C are discussed below.)

3. The engine must be at normal operating temperature as specified by the manufacturer. This temperature is typically 100 °C (212 °F) at thermostat outlet.

4. The engine coolant needs to be a mixture of 50 percent ethylene glycol and 50 percent water. Refer to the fluid recommendations for cold-weather operations.

5. The cabin interior heater must be turned off.

6. If the A/C condenser is ahead of the radiator, the A/C must be run at maximum capacity. If the A/C requires a dedicated fan, the fan must be run at full speed for the duration of the test.

7. Engine water flow as specified by the engine supplier must meet the calculated cooling requirements.

8. Engine coolant thermostat must be blocked open with the engine fan at full speed.

9. Transmission oil flow must meet the recommendations of the supplier.

10. The cooler needs to have the calculated capacity to remove the predicted 80 percent converter efficiency heat load.

Transmission Temperature Limits

The maximum transmission temperatures during testing when adjusted for the local ambient temperature (See Illustration 33.) must not exceed the following:

• Maximum sump temperature must not exceed 121 °C (250 °F).

• Maximum converter outlet temperature must not exceed 149 °C (300 °F).

• Maximum retarder outlet temperature must not exceed 149 °C (300 °F).

Note: Even though maximum temperatures are allowable, the transmissions internal components will have increased durability if the lube oil inlet temperature is kept below 80 °C (180 °F).

Converter 80 Percent Efficiency Requirements

In order to ensure that the OEM vehicle (being evaluated) meets the 80 percent cooling requirement, Caterpillar recommends that all of the vehicle components be tested as a system. Testing the vehicle system ensures that line sizes, routing, and the component locations do not compromise the results. One of the best tests for the 80 percent converter efficiency can be obtained by using a towing dynamometer. Any vehicle can be used as a towed dynamometer that has adequate weight and enough brake cooling capacity to restrain the vehicle being evaluated until the system reaches steady state temperatures. Testing the converter at a particular point on an efficiency curve is difficult. The recommendation is to test at the 80 percent Speed Ratio (i.e. SR) be conducted by testing slightly above and slightly below the 80 percent SR to obtain the recommended 80 percent efficiency point.

Test Results Analysis

Analyze the recorded ambient temperature, the maximum stabilized engine coolant, and transmission oil temperatures reached during the vehicle testing.

1. Calculate the difference between the recorded average ambient temperature during testing and the anticipated maximum ambient where the vehicle will operate. See Illustration 33.

2. Add the calculated difference between the ambient temperature during the test and the maximum anticipated ambient temperatures for the region where the vehicle will operate.

3. Compare the projected temperature results with the additional ambient temperatures added to the test temperatures to the maximum allowable values for the transmission sump and converter out temperatures. The maximum transmission temperature limits are stated in the prior ""Transmission Temperature Limits" "section.

4. If the projected temperature values exceed the operating limits, the OEM is responsible for adding additional cooling capacity to achieve the temperature limit requirements through the following: larger cooler, larger fan and more cooling flow.

Long Term Idling Requirements

Long-term idling for the transmission cooling test is defined as 30 minutes of in gear operations with the parking brake applied. Review vehicle preparation for cooling tests.

1. This test needs to be run at the highest ambient conditions anticipated in the environment where the vehicle is expected to operate. This may be a major factor if the vehicle is expected to operate in stalled inner city traffic where surroundings are restricted.

2. The vehicle temperatures must have reached stable operating conditions prior to starting this test.

3. Engine speeds must be kept at normal idle rpm and not elevated to increase A/C cooling.

4. If the vehicle is equipped with an air conditioner, the air conditioner must be run at maximum capacity and fan speed as already stated in the Steps in ""Vehicle Preparation For Cooling Test" ".

Note: Caterpillar recommends that the operators station be occupied by a driver during the in-gear test. The service and parking brakes need to be applied and the wheel should be blocked.

Long Term Idling Test Results

Apply the same Test Results Analysis as mentioned previously.

Start and Stop Frequency Requirements

The frequent start and stop test only applies to retarder applications.

Perform the following Steps to test 0-30-0 mph by using the retarder to decelerate the vehicle.

1. A fully loaded vehicle and all of the engine and weather conditions mentioned in the previous cooler testing apply to the 0-30-0 test.

2. The test consists of accelerating a loaded vehicle from a standing start to 30 mph by using full engine power. As soon as the vehicle reaches 30 mph, the retarder is fully applied until the vehicle reaches 10 mph. The service brakes are applied to bring the vehicle to a complete stop. This test cycle is repeated as rapidly as possible until the engine and the transmission oil has reached a stabilized temperature.

Perform the following Steps to test 0-40-0 mph by using the retarder to decelerate the vehicle.

1. Applying the same process as in the 0-30-0 testing, repeat the acceleration and retarding by using 40 mph as the top speed.

2. Apply the same Test Results Analysis as mentioned previously.

3. Based upon the customers expected application the OEM can select the more appropriate of the two start/stop cycles for cooling the transmission.

Start and Stop Frequency Test Results

Apply the same Test Results Analysis as mentioned previously.

Downhill Retarder Requirements

Down grade retarder testing requirements will depend upon the following: OEMs requirements, ambient temperature, vehicle loads, grade specifications and desired speeds down grade. If the customers retarder requirements are known, the OEM needs to test at the conditions provided by the end users.

Downhill Testing

The vehicle needs to be properly prepared for a retarder test as discussed previously in this cooler testing section. If the route application for the vehicle is known, the speed limits for the given route should be maintained as close as possible. If the route is not known and the testing is generic, the Interstate Highways grade of 6 percent is recommended. The on grade testing can be simulated by multiplying the vehicle GVW by the percent grade to get the equivalent retarder load. The load at the desired downhill speed can then be simulated in with a drawbar pull test.

ReferenceFor information about the Interstate Highway grades refer to the publication, "A Policy on Geometric Design of Highways and Streets 2001 4th edition".

Example:

• GVW x grade = drawbar required

• 80,000 lb x 0.06 = 4,800 lb

The 4,800 lb of retarder load can be simulated with drawbar test using a rigid load link to measure vehicle retarder resistance. The vehicle with retarder applied in the appropriate downhill gear can then be towed at the desired downhill speed. After the vehicle has reached normal operating temperatures, the drawbar test must be sustained until the retarder cooling requirements reach steady state temperatures.

If the retarder testing is conducted on a downhill grade as compared to the drawbar pull method the service brake may be applied to maintain the downhill speed required for safe operations. Due to the difficulty in maintaining a given speed on the grade or drawbar pull requirement, tests may be necessary to be run above and below the desired test point. Engine speeds, tire sizes, axle ratios, and transmission gears may also create retarder steps within the desired operating range of the retarder. Conducting retarder test runs above and below the desired operating point will allow the OEM to interpolate the test results to meet the desired temperature and cooling requirements.

Downhill Retarder Test Analysis

The downhill retarder testing needs to be analyzed as previously mentioned in the Test Analysis section of this guide adjusting for differences in ambient versus test temperatures.

Oil Cooler Sizing - Without Retarder

Table 15

Maximum Allowable Pressure Drop Across the Transmission Cooler and Lines at Normal Operating Temperature
Speed	Estimated Cooler Flow		Allowable Pressure Drop
RPM	L/min	US gpm	kPa	psi
600	23.1	6.1	48	7
800	34.3	9.1	69	10
1000	45.0	11.9	83	12
1200	56.9	15.0	103	15
1400	68.5	18.1	138	20
1600	78.5	20.7	172	25
1800	89.1	23.5	207	30
2000	100.0	26.4	241	35
2400	112.5	29.7	310	45

Oil Cooler Sizing - With Retarder

Table 16

Maximum Allowable Pressure Drop Across the Transmission Cooler and Lines at Normal Operating Temperature
Engine/Retarder Speed	Retarding Absorption		Transmission Heat Load in Retarding		Est Cooler Oil Flow		Maximum Circuit Cooling Pressure Drop
rpm	hp	kw	BTU/min		L/min	US gpm	kPa	psi
600	13	10	556		58.7	15.5	3	0.5
800	27	20	1147		85.5	22.6	21	3
1000	51	38	2154		113.9	30.1	47	6.8
1200	81	60	3425		135.1	35.7	75	10.9
1400	126	94	5351		163.5	43.2	108	15.7
1600	190	141	8045		189.6	50.1	150	21.8
1800	260	194	11020		214.2	56.6	191	27.7
1900	309	230	13090		226.3	59.8	217	31.4
2000	354	264	15012		240.0	63.4	236	34.2
2100	396	295	16786		246.8	65.2	256	37.2
2200	461	344	19553		260.0	68.7	282	40.9
2300	508	379	21543		269.9	71.3	299	43.4
2400	567	423	24048		280.5	74.1	312	45.2

Note: The pressure drop across the transmission cooler and lines is determined by the differential pressure between the cooler inlet pressure coupler (33) and the cooler outlet pressure coupler (30) in Illustration 2. Excessive cooler pressure drop will reduce cooler oil flow causing overheating, which leads to premature transmission oil deterioration.

Retarder Heat Load

Note: Retarder cooler requirements will demand larger coolers and lines than non-retarder transmissions. Observe the difference in cooler flow rates between Table 15 and Table 16.

Cooling System Checkout

All calculations that were used in the design phase of the cooling package need to be tested in the cooling package application to ensure proper sizing. One or more of the following tests shall be conducted:

• Torque Converter Mode Testing

• Idle Testing

• Retarder Mode Testing

• Start/Stop Testing

• Monitoring in service

Illustration 20	g01255505

Caterpillar recommends that transmission oil cooler and coolant lines be connected so that the transmission oil cooler and coolant lines flow in opposite (i.e. counterflow) directions. Counterflow line routing will maximize cooler performance.

If the oil cooler is mounted in the horizontal plane, the oil ports will purge entrapped air if the coolant lines are mounted on top of the cooler as shown in Illustration 20. If the oil cooler is mounted in the vertical plane, the oil line routing needs to have the inlet on the bottom to purge entrapped air.

Transmission Oil Coolers

The frame mounted Caterpillar Transmission Oil Coolers listed in the following table are given as a reference and as an alternate source of supply for OEMs. The oil coolers listed have been successfully used with the CX31 and CX35 transmissions. OEMs may choose to use existing or locally supplied coolers. The use of the coolers listed does not satisfy the need for a cooling analysis based on vehicle ambients, applications, and the engine and transmission ratings. Caterpillar's concern is that the OEM provide adequate transmission cooling to keep the transmission oil below the temperatures specified.

Table 17

Model	Part Number	Description (1)	Water Connections
CX31 and CX35	238-7997	Single Pass Cast Aluminum 20.1 inch Long 8.7 inch Dia. 36 lb Wt.	Available with 2.5 inch O.D. Water Bonnets
CX31 and CX35	287-6593	Two Pass Cast Aluminum 19.1 inch Long 8.7 inch Dia. 36 lb Wt.	Available with 2.75 inch O.D. Water Bonnets
CX31 and CX35	294-0948	Retarder Cooler Single Pass Cast Iron 40.6 inch Long 9.1 inch Dia. 140 lb Wt.	3.0 inch Water Bonnets

( 1 )

Dimensions and weights are group assembly approximations

Illustration 21	g01365189
(62) Thermostat housing (63) Converter (64) Transmission (65) Oil to cooler (66) Oil from cooler (67) Water pump (68) Radiator

When ambient conditions are very cold and the engine thermostat is closed, a bypass line may be needed on some non-retarder applications to ensure coolant flow to the radiator and the oil cooler as shown in Illustration 22.

Illustration 22	g01365196
(62) Thermostat housing (63) Converter (64) Transmission (65) Oil to cooler (66) Oil from cooler (67) Water pump (68) Radiator (69) Retarder (70) Bypass line

The bypass flow needs to be a high percentage of the available flow when the thermostat is open. Continuous engine coolant flow to the oil cooler provides constant temperature protection for the transmission oil. Caterpillar recommends a bypass line with a minimum ID of 25.4 mm (1 inch). Placing the oil cooler close to the water pump inlet improves cooler performance. The bypass line needs to direct the flow toward the cooler to prevent turbulence and reverse flow to the radiator.

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CX35 Applications

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Output Yoke Selection

The CX35 Transmission has two yoke options. The type of yoke that is chosen needs to suit the OEM in terms of driveline criteria, load, and output speed.

End Yoke Options

Table 18

Yoke Series	Part Number	Maximum Momentary Joint Operating Angle (degrees)
1810	277-0405	29.0
SPL250	277-0403	23.5

Note: The maximum momentary joint operating angle is not a recommended driveline operating angle. The maximum momentary joint operating angle indicates the maximum angle the end yoke can be before interfering with the opposing yoke.

Yoke Retainer Bolt Torque

Apply Loctite® Product 242 or equivalent thread locking compound. You can use either 185-3996 Thread Lock Compound or 9S-3263 Thread Lock Compound . Apply the compound to the threads of the retainer bolt prior to tightening. Tighten the yoke retainer bolt to 270 ± 40 N·m (200 ± 30 lb ft).

Illustration 23	g01204099
(71) Retainer bolt (72) O-ring (73) End yoke (74) Retainer

Driveshaft Requirements

The intent of this driveline/driveshaft section of the Application and Installation Guide is to provide some generic guidelines for OEMs. The OEMs are still responsible for to consulting with the suppliers of the driveline components for analysis and recommendations for specific driveline issues.

The major issues with drivelines and driveshafts are the following: transmitted torque, speed of rotation, alignment angles, driveshaft length and improper driveshaft balance.

Driveshaft Torque

The maximum driveshaft torque can be approximated when the following is known: converter stall torque ratio, transmission gear ratio and engine output torque. Several methods are available in order to determine the correct engine output torque. The best method is to use the maximum engine torque when the engine is at the speed which occurs at converter stall. This number should then be modified as suggested in Step 1 or Step 2 below.

1. Engine gross torque X 0.85 = T(in)

2. Engine net torque X 0.95 = T(in)

3. Torque converter stall torque ratio = (STR)

   1. Usually a number from 1.5 to 2.8

   2. STR = X. XX

4. Transmissions lowest forward gear ratio

   1. LGR = X. XX

5. Transfer case gear ratio (if applicable)

   1. TGR = X. X

6. Transmission efficiency TE = 0.88

Maximum driveline torque can be calculated as shown in the following equation:

T(in) X STR X LGR X TGR X TE = Maximum Torque

Note: Keep in mind that the maximum steady state torque as calculated above might never be reached because wheel slip will occur at a lower torque level. However, dynamic torque spikes, which are higher than the calculated steady state torque values can occur. As a result, maximum driveline torque will be a function of the following: coefficient of traction, weight on the driven axles, tire rolling radius and axle ratio.

Driveshaft Speed

The maximum driveshaft speed can be calculated as shown in the following Steps:

Engine Speed Method 1

1. Engine rpm @ max OEM allowable road speed = E rpm

2. Highest transmission gear ratio = T od

3. (E rpm) /(T od) = Max driveshaft rpm

Road/Vehicle Speed Method 2

1. Maximum vehicle speed in miles/hour = Rs

2. Wheel revolutions per mile = Rev/mi

3. Minutes per Hour = 60

4. Axle ratio = Ar

Rs X Rev/mi / 60 X Ar = Max. driveshaft rpm

The lower driveshaft speed calculated from Method 1 or Method is the correct rpm for the OEMs application.

Caterpillar recommends that driveshaft speeds be kept below 3,000 rpm in order to avoid potential engine and transmission resonance problems.

Note: The highest allowable engine rpm is given in the Truck Engine Performance Manual in the Engine Data Sheets as the high idle rpm. This value may not be reached due to the following: insufficient reserve horsepower, vehicle speed limits imposed by the customer (OEM) and transmission ECU engine overspeed upshift protector.

Driveshaft Balance

If a balanced driveshaft exceeds the critical rpm, increasing the tube diameter or making the driveshaft shorter can raise the driveshaft critical speed. Multiple driveshafts are frequently used to increase the critical speed on a long driveline. A properly phased and balanced driveshaft has the inboard yokes in line with each other. International Standard ISO 1940-1 is an excellent reference for balancing rotating shafts.

Driveshaft Length

Caterpillar recommends a transmission output driveshaft length of between 18 and 57 inches. The length is measured as installed from bearing cap to bearing cap. Field experience indicates that shorter than 18 inch driveshafts have excessive angular displacement with minor suspension travel. Longer than 57 inch driveshafts are heavier and as the splines and joints wear, the driveshafts have a tendency to "whip". Universal joints that operate at a misaligned angle are a common cause of vibration. Driveshaft vibrations can cause problems with the following: transmission, differential, seals and universal joints. Some angularity in the universal joint (i.e. 1 degree) is helpful because angularity causes motion in the U-joint bearings. This motion, along with proper lubrication, will increase U-joint life. A zero angle within the U-joint can cause the U-joint bearings to brinell. Three degrees is considered the maximum for a design where the driveline is not derated for angularity. The angles should be equal to within 1 degree at each end of the driveshaft in order to reduce torsional driveshaft vibration. For motor home applications, the angles at each end of the driveshaft need to be within one half degree for a higher level of customer acceptance.

Driveshaft Angles

Components can be installed so that the alignment creates an angle in two planes. This arrangement creates a compound angle. Most of the design rules for single angles also apply to compound angle arrangements. However, their application is beyond the scope of this Transmission Application and Installation Guide and the OEMs should consult the driveshaft supplier.

Driveshaft Alignment

Another general installation guideline is to keep the centerlines of the components in parallel alignment. The component centerlines need to be parallel when viewed from both the top and side planes. Parallel component alignment will allow the operating driveshaft angles to be equal for reduced torsional vibration. Vibrations will also be reduced if the offset between the parallel planes is minimized.

Summary

The magnitude of driveshaft torsional vibrations is proportional to universal joint operating angle and the speed of rotation. For specific installations and operating limits, the OEMs need to consult the suppliers who provide driveline analysis via the suppliers specialist.

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Transmission Gear Selector/Operator Usage: Shift Pad

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Transmission Control

Warning Light Indicator

Caterpillar requires that OEM transmission users install a RED and AMBER operator warning lamps. The lamps may have several locations within the operators station depending upon the OEMs design. The lamps provide an indication of transmission condition.

1. AMBER Caution Lamp

   The diagnostic lamp is yellow or AMBER. The diagnostic lamp will communicate the status of the transmission electronic system. If the amber lamp (i.e. trouble code) is activated, the amber lamp alerts the operator that a diagnostic condition is active within the transmission. The amber lamp does not require immediate operator attention, but normal operation of the transmission may be affected.

2. RED Warning Lamp

   The RED warning lamp warns the operator of conditions which require immediate attention. The warning lamp indicates either a transmission oil filter bypass or an excessive oil temperature. Immediate operator action is required to reduce transmission oil temperature or to service the oil filters.

3. Fail-In-Gear Operator Information

   The optional fail-in-gear feature allows the transmission to continue to propel the vehicle in the event of certain transmission ECU or vehicle electrical system failures. Lack of electrical power to the ECU is a typical failure mode addressed by the fail-in-gear feature. The transmission shift pad will not respond to shift commands and will display two dashes when the fail-in-gear is active. The fail-in- gear option is intended as a temporary assistance measure so that operators can move the vehicles to a safe location for repairs. The transmission lockup clutch will not engage when the fail-in-gear is active, resulting in significantly reduced engine braking. The fail-in-gear will only select a forward gear if forward is engaged when this option is activated. Transmission neutral can only be achieved by turning the engine off.

Show/hide table

NOTICE
Shutting the engine of may not allow the engine to restart after shutdown. Shutting the engine off will put the transmission in NEUTRAL until repaired. Before shutting off the engine, assure the vehicle is parked in a safe location.

The CX transmissions ECUs provide wiring that allows the OEMs to install a starter interlock. If the OEM does not install the starter interlock, the engine will restart after an ECU failure. However, the transmission will remain in neutral until the ECU is repaired. Caterpillar does not recommend using the starter interlock, if using the starter interlock is the sole purpose to assist Fail-in- Gear operations.

Converter outlet temperature monitors that are ECU driven will not function when the fail-in-gear feature is active. Converter outlet temperatures may reach unacceptable levels if the operator continues to drive the vehicle for an extended period of time in converter drive. To safeguard against unintended converter overheating with the fail-in-gear option, Caterpillar recommends that a secondary converter outlet temperature switch be installed to notify the operator if the converter starts to overheat. A backup switch to monitor transmission oil temperature is not recommended when the OEM uses a non-ECU activated temperature gauge.

A convenient secondary outlet converter temperature switch can be added to the outlet converter line to the cooler. The switch can be set to close at 149° C (300° F), thereby turning on the transmission RED warning lamp.

Operation of the Shift Selector Pad

The transmission control is the operator interface for Caterpillar's CX Series Transmissions.

• The CX35 Transmission Shift Selector Pad has six operator buttons and a two-digit display.

• N Button – The N indicates transmission neutral. Pressing this button will cause the transmission to shift in to neutral.

• D Button – The D indicates transmission forward gears. Pressing this button will cause the transmission to shift into the first forward gear.

• R Button – The R indicates transmission reverse gear. Pressing this button will cause the transmission to shift into the reverse direction gear.

• Mode Button - The Mode button is used to access different shift modes available in the transmission software. This button has an embedded Red LED that will illuminate indicating that the Mode Button has been pressed.

Note: The Mode button may be used to control one of several features enabled through software embedded in the transmissions Electronic Control Unit.

Basic Operation

At ignition Key switch ON, the Shift Selector Pad will display a pair of N's on the display, indicating that the transmission is in Neutral.

Illustration 24	g01315214
(75) Left character (76) Right character

Range Selection

To shift the transmission into a desired Range or Gear, the operator pushes the D for Forward or the R for Reverse.

Note: The transmission will not shift into a range from Neutral or between D and R if the engines RPM is over 1000 RPM.

Forward Range

When D is selected, the Shift Selector Pad will display the maximum gear the transmission has available on the left side of the display. The CX35 transmissions have a maximum of eight forward gears. The transmissions Actual Gear, a 1 (one), will be displayed on the right side of the display as the transmission shifts into first gear.

Illustration 25	g01365200

The Actual Gear will be displayed on the right side of the transmission as the transmission shifts.

Once in a Forward Range, the operator has the ability to force an up or Down shift by pressing one of the arrows on the right side of the Shift Selector Pad.

Reverse Range

To select the Reverse Range, the operator selects the R button. The Shift Selector Pad displays the Desired Gear of R on the left side of the display and N on the right.

Illustration 26	g01300906

When the transmission shifts into Reverse Range, the display will have an R in both locations. There is only one gear in the Reverse range.

Illustration 27	g01301022

Flashing Desired Gear

Several circumstances may prevent the transmission from shifting into a desired Range. When this happens, the Desired Gear value will flash and the transmission will not shift into the selected range.

Illustration 28	g01365204

Circumstances preventing shift into the Desired range include:

• Engine Speed Too high

• Vehicle Speed Too High

• Programmable Parameters

• Auto Neutral

• PTO

• Driveline PTO

• Neutral to Gear Inhibit

• Direction Inhibit

Once the switch and speed requirements have been met the transmission will shift normally. Some circumstances may require the operator to select Neutral range and then reselect the desired range in order for the transmission to shift into that range.

Note: If the Left character "flashes" N, then the transmission is locked in Neutral by the ECU. The most common cause of a "flash" N is when the parking brake is applied. To resume operating, the N button needs to be pressed before the D or R button will respond. The parking brake will still need to be released before driving the vehicle. There are other operations that may cause the "flash" N to be displayed based on how the OEM has requested the ECU to be programmed. See Special Instruction, REHS2791, "Application and Installation Guide (Electrical)" for additional information about the Operators Shift Pad.

Additional Features

Mode Button

The Mode button is available to control a variety of functions. The primary purpose is to select a different shift schedule designed to improve fuel economy. Other modes may be selected through transmission parameter programming. When the Mode button is pushed, the LED in the upper right corner turns ON informing the operator that the selected feature is Active. Pressing the Mode button a second time will disable the feature and the LED will turn OFF.

Illustration 29	g01301284

Oil Level Check

The Caterpillar Shift Selector Pad allows the operator to check the transmissions oil level from the operators station, using an electronic oil level sensor (internal to the transmission).

Vehicle requirements for initiating the Oil Level Check

1. Engine at idle

2. Vehicle stationary

3. Transmission Oil Temperature more than 80 °C (176 °F)

4. Vehicle on Level Ground

5. Transmission in Neutral

To initiate the transmission oil level check, simultaneously press and release the Up and Down arrows on the Shift Selector Pad. This action starts a two-minute timer. If conditions are not correct for the oil level check to take place, the Shift Selector Pad will display one of the following using the range display. The display will only display two characters at a time.

Table 19

Display	Description
OL-EL	Engine Speed too low
OL-EH	Engine Speed too high
OL-XN	Neutral not selected
OL-TL	Oil Temperature too low
OL-TH	Oil Temperature too high
OL-VS	Vehicle speed not zero

Once all conditions are met, the range display will show 24 and will count down to 0 during the two-minute counter period. At the end of two-minute countdown, one of the following will be displayed using the range display, two characters at a time.

Table 20

Display	Description
OL-LO-XX	Oil Level is low by XX quarts
OL-HI-XX	Oil Level is high by XX quarts
OL-OK	Oil Level is full

The Oil Level Message continues to display until the operator exits the mode by pressing a range button or the Up/Down arrows simultaneously. The transmission will not take any action at the end of the oil level check. This check is for the operators information and for the operator to take any appropriate action for an indicated oil level that is either high or low.

Note: Periodically the manual oil level dip stick needs to be compared to the electronic oil level display to insure both methods provide comparable results.

Dual Shift Selector Pads

Some vehicle configurations require that the transmission be temporarily controlled from a remote location. Up to two Shift Selector Pads may be used on one vehicle. A vehicle mounted Shifter Selector switch is used to tell the transmission which shifter is to be in control of shifting. To change between Shift Selector Pads, both shift selector pads must be in Neutral and the vehicle must be stationary. The Shifter Selector switch may then be used to designate which shift selector pad is to be used. The unselected shift selector pad will have a blank display.

____________________

Display Illumination

The displays illumination level is normally tied to the dash illumination level control. An optional vehicle mounted switch, if so equipped, may be used to disable the display.

Modes

Economy Mode

Selecting the Economy mode will reduce the engine speed at which the transmission shifts in order to provide earlier upshifts. This will enhance fuel economy.

PTO ON/OFF

Selecting the PTO mode will engage the control of PTO devices.

Note: This functionality is only available if the PTO is controlled by the transmission ECU.

Hold In Gear

The Hold In Gear feature is used to enable the operator to limit upshifts of the transmission. The transmission will "Hold" the current gear and only upshift to prevent an engine overspeed condition. Normal downshifting is allowed as the vehicle speed decreases. As the transmission downshifts, the hold continues which means that the transmission will stay in the downshifted gear until a mode change is requested, or an overspeed of the engine requires an upshift. The Mode button is used to enable the Hold In Gear feature. If the operator presses and releases the "Hold" button a second time, or selects a different gear the "Hold" function will be disabled. When the Mode button is used as the switch, activating the Hold function will enable the Mode button LED. This LED will remain enabled as long as the Hold feature is active.

____________________

Quick First Gear Limit

The Quick Gear Limit feature utilizes the shift pad MODE switch activation to indicate that the transmission should not upshift beyond 1st gear. This feature can be used to effectively limit vehicle speed during refuse applications. The Quick Gear Limit feature only inhibits upshifts past 1st gear. If the transmission is in 2nd gear, the transmission will continue to operate normally until 1st gear is attained at which upshifts will be inhibited. The Quick First Gear Limit feature may be programmed by OEM vehicle manufacturers to either Enable or Inhibit Reverse gear. Vehicle operation conditions that cause the engine to overspeed in 1st gear will result in an engine-protection upshift to higher gears.

____________________

Maintenance Section

____________________

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NOTICE
The transmission oil filter should be changed on new transmissions after the initial 5,000 miles or 200 hours. The oil does not need to be changed at this time.

Transmission Oil Filters

Either a cartridge filter or a canister (spin-on) filter may be selected to filter the transmission oil. The transmission mounted filter is located on the rear of the transmission.

Usage of a filter, integral or remote mount, is required to remove contaminates that can cause potential damage and/or excessive wear to the planetary gears, bearings and controls. The Caterpillar transmission filter is a high-efficiency filter that removes 98 percent of all particles that are 6 microns and larger. Due to the potential of excessive pressure drop across a filter, only Caterpillar approved filters should be used. Caterpillar requires that all CX Series Transmissions be equipped with a transmission filter as shipped or supplied from the Caterpillar factory. The only exceptions will be when there is written authorization from the Caterpillar Application Account Manager. These exceptions will be primarily limited to large fleets where the consequences can be explained and are understood.

Table 21

CX35 Oil Filters
Filter Type	Element Size	Part Number
cartridge	236 x 102 mm (9.3 x 4.0 inch)	249-2329
spin-on	295 x 116 mm (11.6 x 4.6 inch)	126-1817

Magnetic Filter Screen

A magnetic filter screen is located in the suction tube in the transmission sump. Removing a cover located on the bottom of the transmission oil sump will allow access to the magnetic filter screen. Refer to Illustration 3. To maintain the cleanliness of the fluid, filter changes must be performed as recommended. Remove, clean, and reinstall the magnetic suction screen at each oil and filter change.

Oil and Filter Change Schedules

Severe Application - Vehicles operate both on and off highway. Typical applications are dump trucks, transit mixers, refuse trucks, all-wheel drive public utility trucks, snow removal, yard spotters, and concrete pumpers. Heavy equipment transport and specialty PTO applications are also considered severe applications.

General Application - Vehicles operate exclusively on paved or improved roads. Typical applications are line haul, pickup and delivery, beverage delivery, public service dump, emergency vehicles, and recreational vehicles with living accommodations.

Note: #1. Caterpillar recommends the CX35 main transmission filter be changed after the initial 5,000 miles (8,000 km) or 200 hours of operations, whichever occurs first.

#2. Always inspect and clean the magnetic screen with each oil change.

#3. The breather needs to be cleaned with a petroleum-based solvent at the overhaul or as necessary based on the operating environment.

Table 22

SEVERE APPLICATIONS Dexron® III H
Fluid Change Intervals	Main Filter	Magnetic Screen
12,000 miles (1) (20,000 km) 500 hours 6 months	12,000 miles (20,000 km) 500 hours 6 months	12,000 miles (20,000 km) 500 hours 6 months
SEVERE APPLICATIONS Synthetic ATF Meeting Caterpillar AT-1 Specifications (2) (3)
75,000 miles (4) (120,000 km) 3,000 hours 36 months	75, 000 miles (120,000 km) 3,000 hours 36 months	75,000 miles (120,000 km) 3,000 hours 36 months

( 1 )	Without retarders
( 2 )	Synthetic oil required with retarders
( 3 )	With acceptable SOS oil analysis results every 15,000 miles.
( 4 )	Factory test oil is non-synthetic. Residual oil in the transmission will dilute the 1st use of synthetic oils. Caterpillar recommends a reduced oil change scheduled for the 1st installation of synthetic oils.

Table 23

GENERAL APPLICATIONS Dexron® III H
Fluid Change Intervals	Main Filter	Magnetic Screen
25,000 miles (1) (40,000 km) 1000 hours 12 months	25,000 miles (40,000 km) 1000 hours 12 months	25,000 miles (40,000 km) 1000 hours 12 months
GENERAL APPLICATIONS Synthetic ATF Meeting Caterpillar AT-1 Specifications (2) (3)
150,000 miles (4) (240,000 km) 4,000 hours 48 months	75, 000 miles (120,000 km) 3,000 hours 36 months	75,000 miles (120,000 km) 3,000 hours 36 months

( 1 )	Without retarders
( 2 )	Synthetic oil required with retarders
( 3 )	With acceptable SOS oil analysis results every 30,000 miles.
( 4 )	Factory test oil is non-synthetic. Residual oil in the transmission will dilute the 1st use of synthetic oils. Caterpillar recommends a reduced oil change scheduled for the 1st installation of synthetic oils.

S·O·S Information

S·O·S Services is a highly recommended process for Caterpillar customers to use in order to minimize owning and operating costs. Customers provide oil samples, coolant samples, and other vehicle information. The dealer uses the data in order to provide the customer with recommendations for management of the equipment. In addition, S·O·S Services can help determine the cause of an existing product problem.

Refer to Special Publication, SEBU6250, "Caterpillar Machine Fluid Recommendations" for detailed information concerning S·O·S Services.

Refer to the OMM for a specific sampling location and a service hour maintenance interval for your application.

Consult your Caterpillar dealer for complete information and assistance in establishing an S·O·S program for your equipment.

Transmission Overheating

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NOTICE
In the unlikely event that the transmission does over heat, the transmission should be shifted to neutral and engine speed should be elevated to high idle until the transmission temperature returns to the proper operating temperature. Elevating the engine speed to high idle causes the engine fan to provide the most airflow across the radiator and maximizes oil flow through the cooler.

Towing/Coasting

Since the transmission hydraulic pump is engine driven, the hydraulic pump varies with engine speed. One of the many functions of this pump is to provide lubrication. If the engine speed is non-existent (towing) or at a lower level than intended (coasting), considerations must be taken into account. If the CX35 is installed in a wheeled vehicle that requires towing, the drive shaft must be disconnected from the transmission or the drive axle(s) lifted off the ground. Coasting in NEUTRAL is not recommended by Caterpillar, but if a coasting in neutral situation should occur, engine speed must be elevated to provide proper lubrication to the transmission.

Engine Cranking Requirements

Vehicle manufacturers need to provide adequate cold climate cranking power for the engine and the auxiliary driven components. The transmission converter driven PTOs and any additional OEM mounted equipment on the PTOs add to the cold cranking engine requirements. The following table of temperature vs. torque is typical for a CX35 transmission with no mounted PTO components.

Table 24

CX35	0°C/32°F	80°C / 176°F
RPM	N·m / ft-lb	N·m / ft-lb
0	0	0
50	37/27	19/14
100	71/52	36/26
150	91/67	37/27
200	109/80	37/27
300	123/90	38/28
400	125/92	39/29

____________________

Power Take Off (PTO) Options And Installation Requirements

____________________

Power Take Off (PTO) Options

All CX35 transmissions are capable of driving two side PTOs. The CX35 can be factory ordered with an optional rear PTO. The optional rear PTO can also be installed in the field by removing the rear PTO cover and placing the additional drive shaft and the associated seals and bearings in the transmission. Removing the rear cover plate will allow some transmission oil to drain. Refer to the Disassembly and Assembly, KENR5090. See Illustration 30 for PTO locations.

Bolt on PTO units are available from aftermarket suppliers and can be specified to adapt to a variety of output options. Specifying and designing and installing the PTO devices are the responsibility of the OEM, body builders, and the end user.

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To avoid personal injury due to entanglement with rotating shaft, keep PTO master cover and all power drive system covers in place. Install PTO shaft guard when the system is not in use.

Note: Serious injury can be prevented with proper driveshaft guards. The OEM or the auxiliary PTO installers is responsible for providing guards on exposed rotating parts.

Direction Of Rotation

Engine Rotation SAE J824 - Standard

• Counterclockwise as viewed from the flywheel end of the engine

Transmission Output Rotation

• Forward Same as Input (Converter)

• Reverse Opposite of Input

PTO Rotation

• Side PTO drive gear rotates at engine rpm and same direction as transmission input.

• Rear PTO shaft rotates at 1.25 X Engine rpm and in the opposite direction of transmission input.

Side PTO Torque Limits

Table 25

PTO Configuration	Max Continuous Torque
Single side PTO	950 N·m (700 lb ft)
Multiple PTO total torque (1)	1627 N·m (1200 lb ft)

( 1 )

Each PTO shall not exceed the single PTO maximum torque.

Side PTO Maximum Bending Moment

• From the centerline of the PTO mounting pad: 80 N·m (60 lb ft) maximum (Includes PTO, direct mount pump, and unsupported hydraulic lines).

Illustration 30	g01203627

Transmission PTO Controls

Programmable features, permitting PTO operation under certain parameters, are useful to control PTO operation. These include:

• PTO operation in Neutral only.

• PTO engagement below a specific engine speed.

• Overspeed protection.

PTO Electrical Connections

• Refer to Electrical Application and Installation Guide, REHS2791 for specific OEM electric interface definitions and requirement.

• Refer to the supplier of the PTO attachment for installation instructions of the PTO electrical connections.

Side PTO Interface

Refer to the Installation Dimensions Drawing for details on the side mount PTO pad locations and interface.

Follow all installation instructions supplied by the PTO manufacturer.

Side PTO Mounting Bolts

• M10 x 1.5 externally threaded fastener.

• Minimum fastener Grade 10.9 in accordance with SAE J1199 (1040 MPa min.).

• Minimum quantity of eight bolts are required to secure the PTO to the transmission. Alignment dowels are optional hardware that may be provided by the PTO supplier.

• Torque........................55 ± 5 N·m (41 ± 3.7 lb ft)

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NOTICE
Thread engagement length and bolt torques are critical on the Aluminum Case and Cover of the CX Transmissions. The bolts selected must have a thread engagement length of twice the bolt diameter. Standard torques on short bolts will strip the threads. The bolts must not be too long because the bolts will bottom out and damage the case.

Side PTO Sealing Requirements

• The side mounted PTO shall be sealed to the transmission with a rubber coated metal interface gasket (RCM).

• The RCM gasket supplied by the PTO manufacturer will have the appropriate thickness and tolerance to maintain the required gear center distance. Shimming this PTO is not required.

• The PTO gasket used to seal the PTO cover is intended to be discarded when installing a side PTO.

• Paper gaskets must not be used to seal the PTO to the transmission.

Side PTO Lube and Clutch Pressure Ports

• Two ports are provided, one on the side and one on the rear of the transmission, to provide installation options as required. Refer to Illustration 1 and 2.

• Either port may be used regardless of the PTO mounting pad being utilized. For instance, the rear port may be utilized for an 8 o'clock side mount PTO application.

Rear PTO Torque limits

Maximum output torque permitted at the rear PTO output coupling.

Table 26

PTO Configuration	Max Continuous Torque
Single rear PTO	1356 N·m (1000 lb ft)
Multiple PTO total torque (1)	1627 N·m (1200 lb ft)

( 1 )

Each PTO shall not exceed the single PTO maximum torque.

Rear PTO Maximum Bending Moment

From the rear PTO mounting face: 80 N·m (60 lb ft) maximum bending moment includes PTO, direct mount pump, and unsupported hydraulic lines.

Rear PTO Interface

Removal of the rear PTO cover after the transmission has been properly filled with oil may cause the loss of some fluid. The amount of oil lost will depend upon the installation angle of the transmission and the surface plane of the vehicle when the cover is removed. (Some PTO component suppliers recommend draining the transmission oil prior to installation of PTO components). Check the transmission oil level after installation of PTO components to insure that any oil lost has been replaced and that the added component did not increase the oil requirements of the transmission. The installation dimensional drawings provide additional specifications for the rear PTO mounting pad.

Note: Rear PTO will accept a four bolt SAE J744 "B" pump drive and pilot. A supplier adapter is required to mate with the 17 tooth spline.

Rear PTO Sealing requirements

• The rear PTO is designed for a standard 241 O-ring seal. The Caterpillar part is 6V-1197 O-Ring Seal .

• The O-ring is intended to provide a static radial sealing over the pilot diameter of the unit mating to the rear PTO pad.

• O-ring Seal material: FKM (Viton).

Rear PTO Bolt Requirements

• M12 x 1.75 externally threaded fastener.

• Minimum fastener Grade 10.9 in accordance with SAE J1199 (1040 Mpa min).

• Minimum quantity of eight bolts required to secure the PTO to the transmission.

• Tighten the bolts to a torque of 100 ± 5 N·m (74 ± 3.7 lb ft).

____________________

Support Bracket Locations

____________________

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NOTICE
If bolts are removed from the CX35 transmission to add mounting brackets, etc, they must be replaced with longer bolts so that thread engagement is maintained. The replacement bolts must be of the same grade and torqued to the required specifications. Thread engagement length and bolt torques are critical on the Aluminum Case and Cover of the CX Transmissions. The bolts selected for aluminum threaded bores must have a thread engagement length of twice the bolt diameter. Standard torques on short bolts will strip the threads. The bolts must not be too long because the bolts will bottom out and damage the case.

Illustration 31	g01304450
(84) Bolt locations for support brackets

Illustration 32	g01355737
(85) Bolt locations for support brackets

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Appendix

Transmission Ratings

Table 27

Item Description		CX35
		On-Highway	Severe Duty	Emergency Vehicles	Motorhomes
Maximum Gross Input Power	hp (kW)	625 (466)	625 (466)	625 (466)	625 (466)
Maximum Gross Input Torque	lb-ft (N-m)	2150 (2915)
Maximum Turbine Torque (forward)	lb-ft (N-m)	2350 (3186
Maximum Turbine Torque (reverse)	lb-ft (N-m)	2350 (3186)
Rated Input Speed	rpm	2100
Minimum Input Speed	rpm	600
Maximum Input Speed	rpm	2500
Dry Weight Without Retarder (1)	lb (kg)	1326 (602)
Dry Weight With Retarder (1)	lb (kg)	1476 (670)
Dry Weight Without PTO	lb (kg)	-
Dry Weight With PTO	lb (kg)	-
Forward Reverse Gears		8F/1R
Planetary Gear Ratios
1F		5.73
2F		3.57
3F		2.72
4F		1.95
5F		1.43
6F		1.00
7F		0.74
8F		0.63
1R		-4.46
Overall		9.10
Torque Converters
TC42531		STR 2.7
TC42731		STR 2.3
TC42833		STR 1.9

( 1 )

Does not include crankshaft adapter, flex plates, starter ring gear, bolts, output yoke, and ECU. (29 kg (64 lb))

Description of Applications

On-Highway vehicles operate exclusively on roads that are improved or normally paved. The following are some typical vocations: linehaul, pickup and delivery, beverage delivery, public service dump trucks, utility trucks, tank trucks and tour coaches.

Motorhomes as in recreational vehicles with living accommodations.

Severe Duty vehicles operate both on and off highway. The following are some typical vocations: dump trucks, transit mixers, refuse trucks, all wheel drive public utility trucks, snow removal, yard spotter, concrete pumper, heavy equipment transport and other vocations with severe PTO applications.

Emergency Vehicles as in fire trucks that are typically designed to NFPA guidelines.

Ambient Temperatures

Illustration 33	g01283117

Standard Bolt Torques

Note: The torques in the following tables are based on metric Grade 10.9 or higher fasteners (SAE Grade 8 or higher inch fasteners). Use hardened washers. Split lock washers are not permitted.

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NOTICE
If bolts are removed from the CX35 transmission to add mounting brackets, etc. they must be replaced with longer bolts so that thread engagement is maintained. The replacement bolts must be of the same grade and torqued to the required specifications. Thread engagement length and bolt torques are critical on the Aluminum Case and Cover of the CX Transmissions. The bolts selected for aluminum threaded bores must have a thread engagement length of twice the bolt diameter. Standard torques on short bolts will strip the threads. The bolts must not be too long because the bolts will bottom out and damage the case.

Table 28

Inch Nuts and Bolts
Thread Size Inch	Standard Torque
1/4	12 ± 3 N·m (9 ± 2 lb ft)
5/16	25 ± 6 N·m (18 ± 4 lb ft)
3/8	47 ± 9 N·m (35 ± 7 lb ft)
7/16	70 ± 15 N·m (50 ± 11 lb ft)
1/2	105 ± 20 N·m (75 ± 15 lb ft)
9/16	160 ± 30 N·m (120 ± 22 lb ft)
5/8	215 ± 40 N·m (160 ± 30 lb ft)
3/4	370 ± 50 N·m (275 ± 37 lb ft)
7/8	620 ± 80 N·m (460 ± 60 lb ft)
1	900 ± 100 N·m (660 ± 75 lb ft)
1 1/8	1300 ± 150 N·m (960 ± 110 lb ft)
1 1/4	1800 ± 200 N·m (1320 ± 150 lb ft)
1 3/8	2400 ± 300 N·m (1780 ± 220 lb ft)
1 1/2	3100 ± 350 N·m (2280 ± 260 lb ft)

Table 29

Metric Nuts and Bolts
Thread Size Metric	Standard Torque
M6	12 ± 3 N·m (9 ± 2 lb ft)
M8	28 ± 7 N·m (21 ± 5 lb ft)
M10	55 ± 10 N·m (41 ± 7 lb ft)
M12	100 ± 20 N·m (75 ± 15 lb ft)
M14	160 ± 30 N·m (120 ± 22 lb ft)
M16	240 ± 40 N·m (175 ± 30 lb ft)
M20	460 ± 60 N·m (340 ± 44 lb ft)
M24	800 ± 100 N·m (590 ± 75 lb ft)
M30	1600 ± 200 N·m (1180 ± 150 lb ft)
M36	2700 ± 300 N·m (2000 ± 220 lb ft)

Acronyms

Table 30

Acronyms	Description
A and I	Application and Installation
A/C	Air Conditioner
ABS	Anti-lock Braking System
ADEM	Advanced Diesel Engine Management - control
ATF	Automatic Transmission Fluid
CID	Component Identifier Diagnostic - code that informs the service personnel of specific component or system failure
CTS	Controlled Throttle Shifting - significantly reduces power train stress and clutch wear by controlling engine speed, torque converter lockup, and transmission clutch engagement
ECM	Engine Control Module - controls all aspects of an engines emissions compliance, performance, operator/chassis interaction and diagnostics.
ECU	Electronic Control Unit - electronic device used to control transmission functions
EMS	Electronic Monitoring System
ECPC	Electronic Clutch Pressure Control - design senses input from the transmission and the operator controls in order to modulate each individual clutch through a proportional electro-hydraulic valve
FEA	Finite Element Analysis
FWH	Flywheel Wheel Housing
LUC	Lockup Clutch
OEM	Original Equipment Manufacturer
PT	Power Train - transmission and auxiliary components
PS	Power System - engine, transmission, and cooling system
PTO	Power Take-Off - referred to in this manual is engine rpm control initiated through a dedicated PTO ON/OFF switch circuit connected to the ECM Input No. 1
SAE	Society of Automotive Engineers - standards
STR	Stall Torque Ratio - torque converter stall torque ratio
TBU	Transmission Business Unit
TSG	Technical Standards and Guidelines
ISO	International Standards Organization
OMM	Operation and Maintenance Manual
kPa	x 0.145 = pressure (PSI)
bar	x 14.5 = pressure (PSI)
kW	x 1.34 = horsepower
L/min	x 0.26 = gallons/min
N·m	x 0.74 = ft × lb
SOS	Scheduled Oil Sampling

Installation Dimension Drawings

Illustration 34	g01357273

Illustration 35	g01357277

Illustration 36	g01296707

Illustration 37	g01296616

Illustration 38	g01296623

Illustration 39	g01296648

Illustration 40	g01296654

Illustration 41	g01296686

Illustration 42	g01296697

Illustration 43	g01307629

Illustration 44	g01307660

Illustration 45	g01307686

Illustration 46	g01307970

Illustration 47	g01307977