Bench Test Procedure for a 768C and 769C Off-Highway Truck Transmission {0374, 0599, 0720, 3030, 3064, 3073} Caterpillar

Tractor

768C (S/N: 02X1-UP)

Truck

769C (S/N: 01X1-UP)

Introduction

© 2016 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

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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 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 often used to compare values on portions of transmission tests. 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.

FT Drawings

Illustration 3	g03871891
FT-0669 (A) 168.275 mm (6.625 in) (B) 84.12 mm (3.312 in) (C) 94.28 mm (3.712 in) (D) 94.28 mm (3.712 in) (E) Ø 6.4 ± 0.02 mm (0.252 ± 0.0008 in) (F) 174.625 mm (6.875 in) (G) 87.325 mm (3.438 in) (H) 117.475 mm (4.625 in) (J) 58.725 mm (2.312 in) (K) Ø 13.45 mm (0.531 in) 4 holes (L) 24.6 mm (0.969 in) (M) 49.23 mm (1.938 in) (N) 177.8 mm (7.0 in) (P) 148.37 ± 0.01 mm (5.8415 ± 0.0005 in) (Q) 114.3 mm (4.5 in) (R) 70.37 ± 0.01 mm (2.7705 ± 0.0005 in) (S) 42.875 mm (1.688 in) (T) Ø 92.075 mm (3.625 in) (U) Ø 10.31 mm (0.406 in) (V) 90.07 ± 0.01 mm (3.546 ± 0.0005 in) (W) Ø 8.2 mm (0.323 in) (X) Ø 13.45 mm (0.531 in) (Y) 209.51 ± 0.01 mm (8.2485 ± 0.0005 in) (Z) 206.31 ± 0.01 mm (8.1225 ± 0.0005 in)

Illustration 4	g06072465
FT-1422

Illustration 5	g06072530
FT-1067 (Part 1) (1) Receptacle As MS 3106A-24-7S with MS 3057-16V Cable Clamp Interchangeable with 6D-8151 (2) 16 Conductor Thermoplastic Jacketed Cable with No. 18 Gage Insulated Copper Stranded Wire 838.2 mm (33 in) (3) 2 Conductor Thermoplastic Jacketed Cable with No. 18 Gage Insulated Copper Stranded Wire 635 mm (25 in) (4) 3 Conductor Thermoplastic Jacketed Cable with No. 18 Gage Insulated Copper Stranded Wire 431.8 mm (17 in) (5) 2 Conductor Thermoplastic Jacketed Cable with No. 18 Gage Insulated Copper Stranded Wire 609.6 mm (24 in) (6) Plug As MS 3106A-10SL-4S-020 with Interchangeable with 5S-7433 (7) 1.55 Ø X 12.7 mm (.061 Ø X 0.5 in) Amphenol Pin (8) No. 18 Gage Plastic Insulated Copper Stranded Wire 3048 mm (120 in)

Illustration 6	g06072532
FT-1067 (Part 2)

Illustration 7	g06072562
FT-0980 (1) Rectifier (International - 18-DB4A) (2) H.H. Smith #271 Black (Banana Plug) (3) H.H. Smith #271 Red (Banana Plug) (4) 1 m (3 ft) 2 Conductor Cable-20 Gage (Beldon 8205) (5) 5D-0793 Bulb As - 24V ( 5D-1708 Lamp (Replacement Bulb) (6) Transformer (Triad F4IX ) - Comparable Transformer Required for 50 Hz Power (7) Toggle Switch SPST (Cutler Hammer - 7501K13) (8) Fuse Holder (Bussman HKP) Fuse (Bussman AGC - 1 amp) (9) 3 m (8 ft) Extension Cord - 3 Prong (Beldon - 17408–SJ)

Installation Procedure

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Illustration 8	g06050167
Typical Example

1. Install Tooling (A) on the test bench.
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   Illustration 9	g01105218
   Typical Example

2. Use a hoist to install the transmission on the test bench. The weight of the transmission is 1337 kg (2948 lb).
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   Illustration 10	g06073433

3. Install Tooling (B).
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   Illustration 11	g06073440
   Typical Example

4. Align the transmission with the input drive shaft.

5. Connect the input drive shaft to Tooling (B).
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   Illustration 12	g06073436
   Typical Example

6. Install the drive shaft guard.
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   Illustration 13	g03802221

7. Tighten all four castle nuts and jack bolts.
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   Illustration 14	g06073448

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8. Fasten the transmission to the bench with Tooling (C) on the input end and the output end of the transmission.
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   Illustration 16	g06073482

9. Remove the drain plug from the bottom of the transmission.

10. Remove the cover, the magnetic tube, and the screen from the bottom of housing (1).

    Note: This will allow oil to drain from the transmission during the test procedure.

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    Illustration 17	g06073480

11. Remove the plug from the valve and install Tooling (D).
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12. Remove the cover from the top of the transmission.

13. Install Tooling (E).
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    Illustration 19	g06073491

14. Install Tooling (F).
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    Illustration 20	g06073497

15. Remove the plug and install Tooling (G).
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    Illustration 21	g06073492

16. Remove the plug and install Tooling (H).
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    Illustration 22	g06073501

17. Install Tooling (R) if a Break Valve 9J-6408 is not installed.
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    Illustration 23	g06073520

18. Install Tooling (J).
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    Illustration 24	g06073542

19. Connect hose assembly (2) from the Tooling (R) to the No. 1 flow meter inlet.
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    Illustration 25	g06073526

20. Connect hose assembly (1) from the No. 1 flow meter outlet to Tooling (R).
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    Illustration 26	g06073554
    (4) Pump Inlet

21. Connect hose assembly (4) from the test bench to Tooling (R).
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    Illustration 27	g06073561
    (5) Torque Converter Lockup Clutch Pressure

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

22. Connect pressure line (5) to Tooling (D).
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    Illustration 28	g06073590
    (6) Speed Clutch

23. Connect pressure line (6) to Tooling (E).
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    Illustration 29	g06073577
    (7) Lubrication Pressure

24. Connect pressure line (7) to Tooling (F).
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    Illustration 30	g06073599
    (8) Governor Lubrication Pressure

25. Connect pressure line (8) to Tooling (G).
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    Illustration 31	g06073613

26. Connect air line (9) to Tooling (H).
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    Illustration 32	g06073634
    (10) Pump Pressure

27. Connect pressure line (10).
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    Illustration 33	g06073632

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    Illustration 34	g06073637

28. Connect Tooling (K) to rotary switch (11).
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    Illustration 35	g06073642

29. Connect Tooling (K) to upshift solenoid (12).
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    Illustration 36	g06073649

30. Connect Tooling (K) to downshift solenoid (13).

31. Connect Tooling (K) to Tooling (L).
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    Illustration 37	g06073644

32. Insert one end of jumper wire (14) into pin hole "M" of the other plug assembly of Tooling (K) and the other end of jumper wire (14) to the black terminal on Tooling (L).

    Note: The jumper wire provides a ground circuit for the upshift solenoid and the downshift solenoid.

33. Connect Tooling (M) to the positive terminal and the negative terminal on Tooling (L).

Test Procedure

Solenoid Test

1. Make sure that Tooling (K) is properly connected.

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

3. Record the values in Table 6.

Start Checks

Note: Refer to Testing and Adjusting, SENR6869, "768C and 769C 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. Shift transmission to Neutral position. Supply air to the hold valve at 480 ± 35 kPa (70 ± 5 psi).

3. Adjust the input flow to 68 ± 4 L/min (18 ± 1 US gpm).
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   Illustration 38	g02720621

4. With the transmission in the NEUTRAL position, rotate the input shaft in a counterclockwise direction. Adjust the input rotation to 750 ± 10 rpm.

   Note: The input shaft will be rotated in a counterclockwise direction for the duration of the test. The direction is determined as you face the drive motor of the test bench.

5. The lubrication pressure must be a minimum of 14 kPa (2 psi).

   Note: If there is no lube pressure after 30 seconds, stop input rotation and check connections on test bench and transmission.

6. Record the value in Table 7.

7. Shift the transmission through all gears to eliminate air from the transmission controls.

8. Confirm the correct clutch engagement with Table 4.
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   Table 4

   Clutch Engagement Check
   Gear	Cl 1	Cl 2	Cl 3	Cl 4	Cl 5	Cl 6	Cl 7
   N				X
   R	X						X
   F1	X					X
   F2			X			X
   F3		X				X
   F4			X		X
   F5		X			X
   F6			X	X
   F7		X		X

9. Stop the input rotation.

Pressure Differential Valve

1. Shift the transmission into the reverse position.

2. Adjust the input rotation to 750 ± 10 rpm.

3. Adjust the input flow to 61 ± 4 L/min (16 ± 1 US gpm). The transmission must shift to Reverse.

4. The pump pressure must increase to 3275 ± 35 kPa (475 ± 5 psi). The "P1" pressure must be 310 ± 35 kPa (45 ± 5 psi).

5. Shift the transmission into forward 1. The transmission must shift into forward 7 and the "P1" pressure must remain at 310 ± 35 kPa (45± 5 psi).

6. Shift the transmission into the neutral position. The transmission must shift to Neutral and "P1" pressure must increase to a minimum of 1900 kPa (276 psi).

7. Record the values in Table 8.

Lubrication Pressure

1. Shift the transmission into forward 2.

2. Adjust the input rotation to 2150 ± 50 rpm.

3. Increase the oil inlet flow to 152 ± 10 L/min (40 ± 3 US gpm). Lubrication pressure should be a minimum of 55 kPa (8 psi). If the test bench cannot develop 152 ± 4 L/min (40 ± 1 US gpm), use a flow of 114 L/min (30 US gpm).

4. Record the value in Table 9.

Torque Converter Lockup Clutch

1. Shift the transmission into forward 1.

2. Increase input shaft speed.

3. Supply air to the hold valve at 480 ± 35 kPa (70 ± 5 psi).

4. The torque converter lockup clutch pressure must be 1135 ± 35 kPa (165 ± 5 psi).

5. Gradually reduce the input shaft speed. The torque converter lockup clutch pressure must drop to 0 kPa (0 psi) when the input shaft speed reaches 1390 ± 30 rpm.
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   Illustration 39	g06073656

6. Gradually increase input shaft speed. the lockup clutch pressure must increase to 1517 ± 35 kPa (220 ± 5 psi) when the input shaft speed reaches 1509 ± 15 rpm. If necessary, make an adjustment to the screw under cover (15) to get the correct pressure at the specified engine speed.

7. Shift the transmission into the neutral position.

8. Reduce air pressure to the hold valve to 0 kPa (0 psi).

9. Record the values in Table 10.

Low Idle Pressure

1. Adjust input flow to 64 ± 4 L/min (17 ± 1 US gpm).

2. Adjust input rotation to 750 ± 10 rpm.

3. Shift the transmission into forward 1.

4. Record the Torque Converter Lockup Clutch Pressure, Speed Clutch Pressure "P1", Lubrication Pressure, Governor Lube Pressure, and Pump Pressure values in Table 12.

5. Verify the values with Table 11.

6. Shift the transmission through positions forward 2, forward 3, forward 4, forward 5, forward 6, forward 7, Reverse, and Neutral. Repeat Steps 3 through 5 for each gear range.

   Note: Always shift the transmission back to Neutral when shifting between Forward and Reverse.

7. There must be an indication of lubrication pressure in all gears.

High Idle Pressure

1. Supply air to the hold valve at 480 ± 35 kPa (70 ± 5 psi).

2. Adjust the input flow to 132 ± 19 L/min (35 ± 5 US gpm)

3. Adjust input rotation to 750 ± 10 rpm.

4. Shift the transmission into forward 1.

5. Adjust input rotation to 2300 ± 10 rpm

6. Record the Torque Converter Lockup Clutch Pressure, Speed Clutch Pressure "P1", Lubrication Pressure, Governor Lube Pressure, and Pump Pressure values in Table 14.

7. Verify the values with Table 13.

   Note: Pressure to the torque converter lockup clutch must begin to increase when "P1" pressure reaches 1225 ± 70 kPa (178 ± 10 psi). This must occur in all gears second through seventh.

8. Shift the transmission through positions forward 2, forward 3, forward 4, forward 5, forward 6, forward 7, Reverse, and Neutral. Repeat Steps 3 through 7 for each gear range.

   Note: Always shift the transmission back to Neutral when shifting between Forward and Reverse.

Contamination Control

1. Take an oil sample of the test bench oil supply. Oil contamination must be maximum *ISO 16/13.

2. Record the results in Table .

3. Remove the transmission from the test bench if the test bench oil supply is within specifications.

Transmission Bench Test Data Sheet

Solenoid Test

Start Checks

Pressure Differential Valve

Lubrication Pressure

Torque Converter Lockup Clutch

Low Idle Pressure Check

High Idle Pressure Check

Contamination Control