Bench Test Procedure for a 793, 793B, and 789C Off-Highway Truck Transmission{3030, 3073} Caterpillar

Off-Highway Truck/Tractor:

789C (S/N: 2BW1-UP)

793 (S/N: 3SJ1-UP)

793B (S/N: 1HL1-UP)

Introduction

Table 1

Revision	Summary of Changes in REHS1388
05	Updated Introduction Updated Table 15.
04	Updated Table 7 and Table 17.
03	Updated Introduction. Updated Table 15.
02	Added new introduction and Canceled Part Numbers section.

© 2015 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law. Information contained in this document is considered Caterpillar: Confidential Yellow.

This special instruction contains the necessary information that is required to bench test a specific transmission arrangement. Refer to Table 2 for the correct arrangements. Bench testing the transmission ensures correct assembly and operation of the component. Rotating a transmission provides the most conclusive evaluation. Testing allows the dealer to ensure that the transmission will operate properly in the machine. The specifications in this guideline are specific to bench testing the component. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This guideline must be used with the latest technical information that is available from Caterpillar.

For questions or additional information concerning this guideline, submit a form for feedback in the Service Information System. To address an urgent issue, use the following resources to communicate your request to Caterpillar Repair Process Engineering:

• Caterpillar Dealer Technical Communicator

• Dealer Solution Network

• Caterpillar Technical Representative

• Knowledge Network

Table 2

Machine Model	Transmission Arrangement
789C	6Y-5645
793	6Y-5645
793B	6Y-5645

Canceled Part Numbers and Replaced Part Numbers

This document may include canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Important Safety Information

Illustration 1	g02139237

Follow all safety warnings. Most accidents that involve product operation, maintenance, or repair are caused by failure to observe safety warnings. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. Personnel must be properly trained in order to perform maintenance, repair, or operate any machine. Safety precautions and warnings are provided this instruction and on Caterpillar products. These warnings should be observed before performing any procedures. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are not all inclusive.

The hazards are identified by the "Safety Alert Symbol" which is followed by a "Signal Word" such as "DANGER", "WARNING" or "CAUTION". The "WARNING" Safety Alert Symbol is shown in illustration below.

Illustration 2	g00008666

This safety alert symbol means:

Pay Attention!

Become Alert!

Your Safety is Involved.

The message that appears under the safety alert symbol explains the hazard.

Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The safety information in this document and the safety information on the machine are not all inclusive. Determine that the tools, procedures, work methods, and operating techniques are safe. Determine that the operation, lubrication, maintenance, and repair procedures will not damage the machine. Also, determine that the operation, lubrication, maintenance, and repair procedures will not make the machine unsafe.

The information, the specifications, and the illustrations that exist in this guideline are based on information which was available at the time of publication. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete, most current information before you start any job. Caterpillar dealers can supply the most current information.

Collecting the Test Data

Since conditions vary for each test bench, use the data that is collected from your test bench. The collected data is used to compare test results. The data should be collected and maintained by the operator.

Data from each transmission arrangement is collected and stored. Averages from each transmission arrangement are used to compare values on portions of this transmission test. Always compare data that is collected from the same transmission arrangement that is being tested. Averages for the last 20 transmission arrangements should be maintained.

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Personal injury or death can result from escaping fluid under pressure. Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak.

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Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.

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Personal injury or death can result from not following the proper procedures. To avoid the possibility of injury or death, follow the established procedure.

Tools Needed

Note: Pressures will be sensitive to tooling setup. The diameter of the hose, the diameter of a fitting, and additional filtering can affect pressure. The required tools that are listed in Table 3 were used to develop this test procedure.

Table 3

Required Tools
Tool	Part Number	Part Description	Qty
A	1U-9586	Swivel Head Support Gp	1
	1U-9585	Block Gp (Transmission Mounting)	1
B	1U-8847	Adapter Plate	1
	2H-3740	Bolt (3/4-16X1.25 inch)	4
C	1U-9131	Drive Adapter (Key) (1)	1
D	1U-9359	Drive Adapter (2)	1
E	1U-5935	Plate As (Spindle Adapter)	1
	0L-1178	Bolt (3/4-10X2.0 inch)	2
	5P-8248	Hard Washer	2
	2J-3506	Full Nut	2
	1B-4367	Bolt (5/8-11X3.0 inch)	2
	4B-5275	Washer	2
	1D-4720	Nut	2
	5D-6428	O-Ring Seal	1
F	1U-9722	Load Binder As (Ratchet Type)	4
	138-7575	Link Bracket	2
	1B-4367	Bolt (5/8-11X3.0 inch)	2
G	1U-5999	Spindle Gp	1
	8B-7997	Bolt (1/2-13X2.0 inch)	4
H	1U-8654	Adapter (Splined)	1
T	3B-6552	Elbow	1
	3B-7282	Pipe Nipple	1
	6V-4142	Fitting (Test)	1
J	4C-4898	Cover (Transmission Test)	1
K	1U-8304	Fitting	2
	9U-7446	Adapter	2
	1P-4579	Half Flange	4
	8C-9024	Fitting As (Plain)	2
	6V-3965	Fitting As (Quick Disconnect)	2
	3J-1907	O-Ring Seal	2
	7X-0325	Bolt (1/2-13X2.5 inch)	8
	8T-4223	Hard Washer	8
L	5T-7967	Adapter	1
	5F-8807	Bolt (1/2-13X1.25 inch)	4
M	1U-8301	Fitting	1
	9U-7446	Adapter	1
	1P-4579	Half Flange	2
	8C-9024	Fitting As (Plain)	1
	6V-3965	Fitting As (Quick Disconnect)	1
	3J-1907	O-Ring Seal	1
	9S-1366	Bolt (1/2-13X1.25 inch)	4
	8T-4223	Hard Washer	4
N	6V-3965	Fitting As	1
	3J-1907	O-Ring Seal	1
U	8J-7844	Adapter Fitting	1
	6V-3966	Fitting As (Valve)	1
	3K-0360	O-Ring Seal	1
P	9U-7500	Transmission Analyzer Tool Gp	1
	9U-7498	Adapter Cable As (Transmission Analyzer)	1
	1U-9482	Adapter Cable As	1
	4C-5974	Cable Adapter	1
Q	8T-0855	Pressure Gauge (0 to 4,000 kPa (0 to 580 psi))	10
	6V-3989	Fitting (Test)	10
	177-7861	Hose As	10
	6V-4143	Coupler	20
R	8T-0863	Pressure Gauge (0 to 250 kPa (0 to 36 psi))	2
	6V-3989	Fitting (Test)	2
	177-7861	Hose As	2
	6V-4143	Coupler	4

( 1 )	This drive adapter is used with the small drive shaft.
( 2 )	This drive adapter is used with the large drive shaft.

Tools Needed (Optional Procedure)

Illustration 3	g01012642

Table 4

Required Tools
Tool	Part Number	Part Description	Qty
S	131-5050	Dataview Tool Gp (1)	1
	148-9610	Computer Cart Gp	1
	4C-6818	Pressure Sensor (0 to 500 psi)	5
	6V-4144	Coupler	5
	131-5054	Adapter Cable As (Pressure Sensor)	5
	6V-2198	Cable	5

( 1 )

The compatible computer system is not included.

Installation Procedure

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Illustration 4	g00913597

1. Install Tooling (A) on the rails of the test bench, as shown.

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Illustration 5	g00913598

2. Use a hoist to install the transmission on the test bench. The weight of the transmission is 1906 kg (4203 lb).

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Illustration 6	g00913599

3. Install Tooling (B) to the input yoke.

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Illustration 7	g00913600

4. Install Tooling (C) on Tooling (B) .

   Note: Tooling (C) will adapt to the small drive shaft. If you are using the large drive shaft, install Tooling (D) on Tooling (C) .

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Illustration 8	g00913601

5. Align the transmission with the input drive shaft.

6. Connect the input drive shaft to Tooling (C) .

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Illustration 9	g00913602

7. Install the drive shaft guard.

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Illustration 10	g00913603

8. Use a hoist to install Tooling (E) on the transmission case. The weight of Tooling (E) is 50 kg (110 lb).

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Illustration 11	g00913604

9. Install two bolts in the bottom locations, as shown.

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Illustration 12	g00913605

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Illustration 13	g00913606

10. Install Tooling (F) in the top locations, as shown.

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Illustration 14	g00913607

11. Install Tooling (F) to the input end of the transmission.

12. Install Tooling (F) to the output end of the transmission.

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Illustration 15	g00913608

Note: Refer to Special Instruction, SEHS8763, "Assembly and Operation of 1U-5999 Spindle Group Used for Testing Transmissions on Hydraulic Test Bench" for additional information.

13. Remove the drawbar bolt from Tooling (G) .

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Illustration 16	g00913609

14. Lubricate the outer diameter of Tooling (H) .

15. Install Tooling (H) in Tooling (G) .

16. Install the drawbar bolt. Tighten the drawbar bolt to retain Tooling (H) in Tooling (F). The correct torque is 170 N·m (125 lb ft).

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Illustration 17	g00913613

17. Use a hoist to install Tooling (G) on Tooling (E). The weight of Tooling (G) is 121.140 kg (267 lb).

18. Carefully install Tooling (G) on Tooling (E). Tooling (H) will slide on the transmission output shaft.

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Illustration 18	g00913615

19. Loosen bolt (1) .

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Illustration 19	g00913616

20. Use bolt (2) to adjust Tooling (G) inward until Tooling (H) contacts the carrier.

    Note: Refer to Special Instruction, SEHS8763, "Assembly and Operation of 1U-5999 Spindle Group Used for Testing Transmissions on Hydraulic Test Bench" for additional information.

21. Adjust Tooling (G) in order to provide a 3.0 - 4.0 mm (0.12 - 0.16 inch) gap spacing between Tooling (G) and Tooling (H) .

    Note: The measurement may be taken through the access hole in Tooling (E) .

22. Tighten bolt (1) .

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Illustration 20	g00913659

23. Remove bracket (3) .

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Illustration 21	g00913660

24. Remove cover (4) .

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Illustration 22	g00913663

25. Remove plug (5) .

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Illustration 23	g03329503

26. Install Tooling (T) .

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Illustration 24	g00913668

27. Install Tooling (J) .

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Illustration 25	g00913618

28. Install Tooling (K) .

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Illustration 26	g00913669

29. Install Tooling (L) .

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Illustration 27	g00914112

30. Install Tooling (M) .

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Illustration 28	g00913683

31. Remove filter assembly (6) .

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Illustration 29	g00913685

32. Remove drain plug (7) .

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Illustration 30	g00913686

33. Remove plug (8) .

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Illustration 31	g00913688

34. Install Tooling (N) .

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Illustration 32	g00913691

35. Remove fitting (9) .

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Illustration 33	g03329505

36. Install Tooling (U) .

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Illustration 34	g00913698
Transmission Supply Port

37. Connect hose assembly (10) from the pressurized flow meter to Tooling (K) .

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Illustration 35	g00913699
Oil Cooler Outlet

38. Connect hose assembly (11) from the No. two flow meter to Tooling (K) .

    Note: The No. 2 flow meter will measure the output flow that is returning to the transmission lube port.

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Illustration 36	g00913700
Transmission Lube Port

39. Connect hose assembly (12) from the outlet of the No. two flow meter to Tooling (M) .

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Illustration 37	g00913706

40. Connect lube line (13) from the test bench to Tooling (G). Maintain an oil pressure of 275 kPa (40 psi).

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Illustration 38	g00913718
(14) Pressure tap "A" for the No. 2 clutch (15) Pressure tap "B" for the No. 1 clutch (16) Pressure tap "C" for the No. 3 clutch (17) Pressure tap "D" for the lockup dual stage relief valve (18) Pressure tap "E" for the No. 4 clutch (19) Pressure tap "F" for the No. 5 clutch (20) Pressure tap "G" for the No. 6 clutch

Note: If you are using individual pressure gauges to measure the pressures, refer to Table 3 for the correct pressure gauges.

41. Connect Tooling (Q) to pressure taps (14), (15), (16), (17), (18), (17), and (18), as shown.

    Note: Pressure tap "H" is not used.

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Illustration 39	g03329510
Pressure Tap for the Pilot Oil Pressure

42. Connect Tooling (Q) to Tooling (T) .

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Illustration 40	g03329513
Pressure tap for the Lockup Clutch Pressure

43. Connect Tooling (Q) to Tooling (U) .

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Illustration 41	g00913737
(21) Pressure Tap for the Transmission Charging Pump

44. Connect Tooling (Q) to pressure tap (21) .

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Illustration 42	g00913741
(22) Pressure Tap for the Transfer Gear Lube

45. Connect Tooling (R) to pressure tap (22) .

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Illustration 43	g00913746
Pressure Tap for the Planetary Lube Circuit

46. Connect Tooling (R) to Tooling (N) .

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Illustration 44	g00913748
(24) Upshift Solenoid (25) Downshift Solenoid (26) Lockup Clutch Solenoid

47. Connect Tooling (P) to solenoid (24), solenoid (25), and solenoid (26), as shown.

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Illustration 45	g00913752

48. Connect Tooling (P) to harness connector (27), as shown.

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Illustration 46	g00913753

49. Connect Tooling (P) to a suitable location, as shown.

Test Procedure

Solenoid Test

1. Make sure that the harness is properly connected.

2. Use Tooling (P) to perform the solenoid test.

3. Record the values in Table 9.

Start Checks

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Personal injury or death can result from not following the proper procedures. To avoid the possibility of injury or death, follow the established procedure.

Note: Refer to Testing and Adjusting, SENR1523, "789C Off-Highway Truck Power Train" for the correct adjusting procedures.

1. If you are using SAE 10W oil, warm the oil to 50 °C (125 °F). If you are using Mobil DTE11 oil, warm the oil to 34 °C (95 °F). Maintain this temperature for the duration of the test.

2. Adjust the input flow to 65 ± 4 L/min (17 ± 1 US gpm).

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Illustration 47	g02720621

3. With the transmission in the NEUTRAL position, rotate the input shaft in a counterclockwise direction. Adjust the input rotation to 600 ± 30 rpm.

4. Shift the transmission through all speed ranges to eliminate air from the transmission controls.

5. Check for lockup or excessive drag in all ranges.

6. Adjust the input rotation to 0 rpm.

7. Use the following procedure to test the transmission.

Priority Reducing Valve

1. Adjust the input flow to 65 ± 4 L/min (17 ± 1 US gpm).

2. Adjust the input rotation to 800 ± 30 rpm in the NEUTRAL 2 position.

3. Shift the transmission to the FORWARD 1 position.

4. Check the pressure for the priority reducing valve. The correct pressure must be 1725 ± 70 kPa (250 ± 10 psi).

5. Record the value in Table 10.

Neutralizer Valve

Note: Eliminate all incoming flow before performing this test. This procedure may be necessary for you to shut down the test bench.

1. Stop the input rotation in any range. Do not stop the input rotation in NEUTRAL 1 or NEUTRAL 2. Stop input to the transmission.

2. Adjust the input flow to 65 ± 4 L/min (17 ± 1 US gpm).

3. Adjust the input rotation to 800 ± 30 rpm.

4. The neutralizer valve must prevent a pressure increase at any clutch station.

5. Record the values in Table 11.

6. Shift the transmission to the NEUTRAL 1 position. The clutch pressure that is measured at pressure tap "C" must rise to a normal pressure.

7. Record the value in Table 12.

Lube Circuit Check

1. Shift the transmission to FORWARD 2.

2. Adjust the input rotation to 1850 ± 30 rpm.

3. Adjust the input flow until the lube flow is 152 ± 4 L/min (40 ± 1 US gpm). Maintain this flow during this check.

4. The lube pressure must be within 7 kPa (1 psi) of the average for this arrangement. The reference for the transfer gear lube is 38 ± 7 kPa (5.5 ± 1 psi). The reference for the planetary lube circuit is 41 ± 7 kPa (6 ± 1 psi).

5. Record the value in Table 13.

6. Stop the input rotation.

7. Stop the input flow.

Primary Clutch Pressure Checks

1. Remove Tooling (J) .

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Illustration 48	g00913757

2. Remove the load piston plugs (28) from selector valve "A", "B", "C", "E", "F", and "G".

   Note: DO NOT remove the load piston plug from selector valve "D".

3. Install Tooling (H) .

4. Adjust the input flow to 65 ± 4 L/min (17 ± 1 US gpm).

5. The lockup solenoid must be de-energized.

6. Adjust the input rotation to 800 ± 30 rpm.

7. Shift the transmission through each gear range.

8. Record the primary clutch pressure for each gear range in Table 14.

9. Verify that the primary clutch pressures match the values in Table 5.

Table 5

Primary Clutch Pressure In Torque Converter Drive
Station (1) (2)		"A"	"B"	"C"	"E"	"F"	"G"
Clutch		No. 2	No. 1	No. 3	No. 4	No. 5	No. 6
Speed Position	Engaged Clutches	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)
NEUTRAL 1	3	0	0	480 kPa (70 psi)	0	0	0
NEUTRAL 2	1	0	475 kPa (69 psi)	0	0	0	0
REVERSE	1 and 6	0	475 kPa (69 psi)	0	0	0	425 kPa (62 psi)
FIRST	1 and 5	0	475 kPa (69 psi)	0	0	450 kPa (65 psi)	0
SECOND	2 and 5	525 kPa (76 psi)	0	0	0	450 kPa (65 psi)	0
THIRD	1 and 4	0	475 kPa (69 psi)	0	425 kPa (62 psi)	0	0
FOURTH	2 and 4	525 kPa (76 psi)	0	0	425 kPa (62 psi)	0	0
FIFTH	1 and 3	0	475 kPa (69 psi)	480 kPa (70 psi)	0	0	0
SIXTH	2 and 3	525 kPa (76 psi)	0	480 kPa (70 psi)	0	0	0

( 1 )	Station "H" is not used.
( 2 )	Station "D" does not control a clutch. When the lockup clutch solenoid is activated, Station "D" reduces the pressure setting of the dual stage relief valve. The action of Station "D" on the ICM transmission hydraulic control maintains the oil in the clutch supply rail at a reduced pressure. Refer to the Testing and Adjusting, "Transmission Hydraulic Control (Pressure Pack) - Test and Adjust" for the proper procedure to adjust Station "D".
( 3 )	The tolerance is + 50 − 35 kPa (+ 7 − 5 psi).

Final Pressure Checks (Low Idle)

1. Install load piston plugs (12). Refer to Special Instruction, "Primary Clutch Pressure Checks".

2. Install Tooling (J) .

3. Adjust the input flow to 65 ± 4 L/min (17 ± 1 US gpm).

4. Adjust the input rotation to 800 ± 30 rpm.

5. Shift the transmission through ranges NEUTRAL 2, REVERSE, and FORWARD 1.

6. Record the clutch pressure for each gear range in Table 16.

7. Verify that the clutch pressures match the values in Table 6.

Table 6

Clutch Pressure in Torque Converter Drive With The Engine At Low Idle rpm
Station (1) (2)		"A"	"B"	"C"	"E"	"F"	"G"
Clutch		No. 2	No. 1	No. 3	No. 4	No. 5	No. 6
Speed Position	Engaged Clutches	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)
NEUTRAL 2	1	0	2760 kPa (400 psi)	0	0	0	0
REVERSE	1 and 6	0	2760 kPa (400 psi)	0	0	0	2760 kPa (400 psi)
FIRST	1 and 5	0	2760 kPa (400 psi)	0	0	2585 kPa (375 psi)	0

( 1 )	Station "H" is not used.
( 2 )	Station "D" does not control a clutch. When the lockup clutch solenoid is activated, Station "D" reduces the pressure setting of the dual stage relief valve. The action of Station "D" on the ICM transmission hydraulic control maintains the oil in the clutch supply rail at a reduced pressure. Refer to the Power Train Testing and Adjusting, "Transmission Hydraulic Control (Pressure Pack) - Test and Adjust" for the proper procedure to adjust Station "D".
( 3 )	The tolerance is + 240 − 100 kPa (+ 35 − 15 psi).

Dual Stage Relief Valve

1. Adjust the input flow to 65 ± 4 L/min (17 ± 1 US gpm).

2. Energize the lockup clutch solenoid.

3. Disconnect the harness connector from the lockup clutch solenoid.

4. Adjust the input rotation to 800 ± 30 rpm.

5. Shift the transmission to the FORWARD 2 position.

6. Check the pump pressure. The minimum pump pressure is 2515 kPa (365 psi).

7. Record the value in Table 15.

8. Adjust the input flow to 150 ± 4 L/min (39 ± 1 US gpm).

9. Adjust the input rotation to 1850 ± 30 rpm.

10. Check the pump pressure. Reference is 3206 kPa (465 psi).

11. Record the value in Table 15.

12. Connect the harness connector to the lockup clutch solenoid.

13. Check the pump pressure. The pump pressure is 2100 ± 105 kPa (305 ± 15 psi).

14. Record the value in Table 15.

15. If the pump pressure is not correct, adjust the pressure. Refer to Testing and Adjusting, SENR1523, "789C Off-Highway Truck Power Train" for the correct adjusting procedures.

16. Disconnect the harness connector to the lockup clutch solenoid.

17. Check the pump pressure. The pump pressure should be 3070 kPa (445 psi).

18. Adjust the input flow to 57 ± 4 L/min (15 ± 1 US gpm).

19. Adjust the input rotation to 800 ± 30 rpm.

20. Check the pump pressure. The pump pressure should be 2760 kPa (400 psi).

21. Record the value in Table 15.

Final Pressure Checks (High Idle)

1. The lockup clutch solenoid must be de-energized.

2. Adjust the input flow to 150 ± 4 L/min (39 ± 1 US gpm).

3. Adjust the input rotation to 800 ± 30 rpm with the transmission in the NEUTRAL 1 position.

4. Adjust the input rotation to 1850 ± 30 rpm.

5. Record the clutch pressure in Table 17.

6. Adjust the input rotation to 800 ± 30 rpm.

7. Shift the transmission through positions NEUTRAL 2, REVERSE, and FORWARD 1. Repeat Steps 4 through 6 for each gear range.

8. Adjust the input rotation to 800 ± 30 rpm with the transmission in the FORWARD 1 position.

9. Energize the lockup clutch solenoid.

10. Adjust the input rotation to 1850 ± 30 rpm.

11. Record the clutch pressure in Table 17.

12. Adjust the input rotation to 800 ± 30 rpm.

13. Shift the transmission through positions FORWARD 1, FORWARD 2, FORWARD 3, FORWARD 4, FORWARD 5, and FORWARD 6. Repeat Steps 10 through 12 for each gear range.

14. Verify that the clutch pressures match the values in Table 7.

Table 7

Clutch Pressure With The Engine At High Idle rpm
Station (1) (2)		"A"	"B"	"C"	"E"	"F"	"G"
Clutch		No. 2	No. 1	No. 3	No. 4	No. 5	No. 6
Torque Converter Drive
Speed Position	Engaged Clutches	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)	Pressure (3)
NEUTRAL 1	3	0	0	2470 kPa (358 psi)	0	0	0
NEUTRAL 2	1	0	2890 kPa (419 psi)	0	0	0	0
REVERSE	1 and 7	0	2890 kPa (419 psi)	0	0	0	2805 kPa (407 psi)
FIRST	2 and 6	0	2890 kPa (419 psi)	0	0	2720 kPa (395 psi)	0
Direct Drive
SECOND	2 and 5	2020 kPa (293 psi)	0	0	0	2020 kPa (293 psi)	0
THIRD	1 and 4	0	2020 kPa (293 psi)	0	2020 kPa (293 psi)	0	0
FOURTH	2 and 4	2020 kPa (293 psi)	0	0	2020 kPa (293 psi)	0	0
FIFTH	1 and 3	0	2020 kPa (293 psi)	2020 kPa (293 psi)	0	0	0
SIXTH	2 and 3	2020 kPa (293 psi)	0	2020 kPa (293 psi)	0	0	0

( 1 )	Station "H" is not used.
( 2 )	Station "D" does not control a clutch. When the lockup clutch solenoid is activated, Station "D" reduces the pressure setting of the dual stage relief valve. The action of Station "D" on the ICM transmission hydraulic control maintains the oil in the clutch supply rail at a reduced pressure. Refer to the Power Train Testing and Adjusting, "Transmission Hydraulic Control (Pressure Pack) - Test and Adjust" for the proper procedure to adjust Station "D".
( 3 )	The tolerance is + 240 − 100 kPa (+ 35 − 15 psi).

Transmission Bench Test Data Sheet

Table 8

CATERPILLAR	Transmission Bench Test Data Sheet	Test Date:
		Model:793 793B 789C
Work Order:		Serial No.:

Solenoid Test

Table 9

Solenoid Test	Solenoid 1	Solenoid 2	Solenoid 3
	_______ ohms	_______ ohms	_______ ohms

Priority Reducing Valve

Table 10

Priority Reducing Valve

Input Speed (800 ± 30 rpm) Input Flow 65 ± 4 L/min (17 ± 1 US gpm)

kPa (psi)

Neutralizer Valve

Table 11

Neutralizer Valve (Step 1)			Input Speed (800 ± 30 rpm) Input Flow 65 ± 4 L/min (17 ± 1 US gpm)
A	B	C	D	E	F	G
kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)	kPa (psi)

Table 12

Neutralizer Valve (Step 2)		Gear Range NEUTRAL 1
Station	C	kPa (psi)	The clutch pressure must rise to normal pressure.		Yes	No

Lube Circuit Check

Table 13

Lube Circuit Check		Gear Range FORWARD 2 Input Speed (1850 ± 30 rpm) Lube Flow 152 ± 4 L/min (40 ± 1 US gpm)
Test Bench Average		Average	Actual
Transfer Gear Lube Pressure		kPa (psi)	kPa (psi)
Planetary Lube Circuit Pressure		kPa (psi)	kPa (psi)

Primary Pressure Checks

Table 14

Primary Pressure Checks			The Load Pistons are Removed. Input Speed (800 ± 30 rpm) Input Flow 65 ± 4 L/min (17 ± 1 US gpm)
Station	Clutch	Specification (1)	Original Pressure	Amount of Adjustment	Last Pressure
A	2	525 kPa (76 psi)
B	1	475 kPa (69 psi)
C	3	480 kPa (70 psi)
E	4	425 kPa (62 psi)
F	5	450 kPa (65 psi)
G	6	425 kPa (62 psi)

( 1 )

The tolerance is + 50 − 35 kPa (+ 7 − 5 psi).

Dual Stage Relief Valve

Table 15

Dual Stage Relief Valve	Input Speed (800 ± 30 rpm) Input Flow 65 ± 4 L/min (17 ± 1 US gpm) MIN 2515 kPa (365 psi)			kPa (psi)
	Input Speed (1850 ± 30 rpm) Input Flow 148 ± 4 L/min (39 ± 1 US gpm) REFERENCE 3206 kPa (465 psi)			kPa (psi)
	Input Speed (1850 ± 30 rpm) Input Flow 148 ± 4 L/min (39 ± 1 US gpm) REFERENCE 2103 kPa (305 psi) Direct Drive			kPa (psi)
	Input Speed (800 ± 30 rpm) Input Flow 57 ± 4 L/min (15 ± 1 US gpm) REFERENCE 2760 kPa (400 psi) Direct Drive			kPa (psi)

Final Pressure Checks (Low Idle)

Table 16

Final Pressure Checks (Low Idle)		Install the Load Pistons. Input Speed (700 ± 30 rpm) Lube Flow 57 ± 4 L/min (15 ± 1 US gpm)
Station		"A"	"B"	"C"	"E"	"F"	"G"
Clutch		No. 2	No. 1	No. 3	No. 4	No. 5	No. 6
Torque Converter Drive
Speed Position	Engaged Clutches	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
NEUTRAL 2	1
REVERSE	1 and 6
FIRST	1 and 5

Final Pressure Checks (High Idle)

Table 17

Final Pressure Checks (High Idle)		Input speed (1850 ± 30 rpm) Input flow 150 ± 4 L/min (39 ± 1 US gpm)
Station		"A"	"B"	"C"	"E"	"F"	"G"
Clutch		No. 2	No. 1	No. 3	No. 4	No. 5	No. 6
Torque Converter Drive
Speed Position	Engaged Clutches	Pressure	Pressure	Pressure	Pressure	Pressure	Pressure
NEUTRAL 1	3
NEUTRAL 2	1
REVERSE	1 and 6
FIRST	1 and 5
Direct Drive
SECOND	2 and 5
THIRD	1 and 4
FOURTH	2 and 4
FIFTH	1 and 3
SIXTH	2 and 3

ISO Particle Count

Table 18

ISO Particle Count

Sample the test bench oil supply.

________/________Particle Count

Table 19

______________________________________ Technician

______________________________________ Supervisor

Shift Traces (Optional Procedure)

Introduction

Shift traces have become an important tool for validating the proper operation and assembly of the component. The shift cycles are recorded and reviewed to analyze the specific segments of the shift cycle. The segments are decay times, fill times, and modulation times. Shift traces can reveal faulty parts or omitted parts. Shift traces can alert the technician to potential problems.

Correct interpretation of terminology is essential for understanding shift traces. Refer to Illustration 50 and Illustration 51 to interpret your shift traces correctly.

Collecting the Test Data

Since conditions vary for each test bench, use the data that is collected from your test bench. The collected data is used to compare test results. The data should be collected and maintained by the operator.

Data from each transmission arrangement is collected and stored. Averages from each transmission arrangement are used to compare values on portions of this transmission test. Always compare data that is collected from the same transmission arrangement that is being tested. Averages for the last 20 transmission arrangements should be maintained.

These averages should be entered on the shift trace analysis worksheets. A shift trace is included on each worksheet.

Note: Refer to Table 4 for the required tooling.

Show/hide table



Illustration 49	g00915182

1. Install Tooling (U) on pressure taps, "A", "B", "C", "E", and "F".

Illustration 50	g00899108

Illustration 51	g00899331

Shift Trace (FORWARD 2 to FORWARD 3)

Table 20

Data View Graph Definition
Selected Channels	1, 2, 4, 5
Maximum Pressure	3445 kPa (500 psi)
Input Shaft Speed	900 rpm

Table 21

Channel Assignments
Data Channel		1	2	4	5
Clutch		1	2	4	5
Sample Rate		100 per sec

Illustration 52	g00915185

Table 22

Shift Trace Analysis Worksheet
Description	Clutch	Target	Test Bench Data History	Actual
Decay Time	2	.110 sec ± 15%	_____________ sec	_____________ sec
Decay Time	5	.150 sec ± 15%	_____________ sec	_____________ sec
Fill Time	1	.340 sec ± 15%	_____________ sec	_____________ sec
Fill Time	4	.288 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	1	.300 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	4	.290 sec ± 15%	_____________ sec	_____________ sec

Shift Trace (FORWARD 3 to FORWARD 4)

Table 23

Data View Graph Definition
Selected Channels	1, 2, 4
Maximum Pressure	3445 kPa (500 psi)
Input Shaft Speed	900 rpm

Table 24

Channel Assignments
Data Channel		1	2	4
Clutch		1	2	4
Sample Rate		100 per sec

Illustration 53	g00915186

Table 25

Shift Trace Analysis Worksheet
Description	Clutch	Target	Test Bench Data History	Actual
Decay Time	1	.150 sec ± 15%	_____________ sec	_____________ sec
Fill Time	2	.350 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	2	.330 sec ± 15%	_____________ sec	_____________ sec

Shift Trace (FORWARD 4 to FORWARD 5)

Table 26

Data View Graph Definition
Selected Channels	1, 2, 3, 4
Maximum Pressure	3445 kPa (500 psi)
Input Shaft Speed	900 rpm

Table 27

Channel Assignments
Data Channel		1	2	3	4
Clutch		1	2	3	4
Sample Rate		100 per sec

Illustration 54	g00915187

Table 28

Shift Trace Analysis Worksheet
Description	Clutch	Target	Test Bench Data History	Actual
Decay Time	2	.110 sec ± 15%	_____________ sec	_____________ sec
Decay Time	4	.120 sec ± 15%	_____________ sec	_____________ sec
Fill Time	1	.340 sec ± 15%	_____________ sec	_____________ sec
Fill Time	3	.200 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	1	.300 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	3	.250 sec ± 15%	_____________ sec	_____________ sec

Shift Trace (FORWARD 5 to FORWARD 6)

Table 29

Data View Graph Definition
Selected Channels	1, 2, 3
Maximum Pressure	3445 kPa (500 psi)
Input Shaft Speed	900 rpm

Table 30

Channel Assignments
Data Channel		1	2	3
Clutch		1	2	3
Sample Rate		100 per sec

Illustration 55	g00915190

Table 31

Shift Trace Analysis Worksheet
Description	Clutch	Target	Test Bench Data History	Actual
Decay Time	1	.150 sec ± 15%	_____________ sec	_____________ sec
Fill Time	2	.340 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	2	.330 sec ± 15%	_____________ sec	_____________ sec

Shift Trace (FORWARD 3 to FORWARD 2)

Table 32

Data View Graph Definition
Selected Channels	1, 2, 4, 5
Maximum Pressure	3445 kPa (500 psi)
Input Shaft Speed	900 rpm

Table 33

Channel Assignments
Data Channel		1	2	4	5
Clutch		1	2	4	5
Sample Rate		100 per sec

Illustration 56	g00915192

Table 34

Shift Trace Analysis Worksheet
Description	Clutch	Target	Test Bench Data History	Actual
Decay Time	1	.15 sec ± 15%	_____________ sec	_____________ sec
Decay Time	4	.120 sec ± 15%	_____________ sec	_____________ sec
Fill Time	2	.290 sec ± 15%	_____________ sec	_____________ sec
Fill Time	5	.430 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	2	.330 sec ± 15%	_____________ sec	_____________ sec
Modulation Time	5	.490 sec ± 15%	_____________ sec	_____________ sec