Bench Test Procedure For A 777G Off-Highway Truck Transmission {0784, 3030, 3139, 3167} Caterpillar

Off Highway Truck

777G (S/N: GT71-UP; T5A1-UP; TNM1-UP; RDR1-UP; T4Y1-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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• Caterpillar Technical Representative

• Knowledge Network

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

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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.

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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. Caterpillardealers 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	g06057799
FT-3194 Note A: For pin (17) (Jumpered to pin (15))

Installation Procedure

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1. Install Tooling (A) to the test bench.
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2. Remove threaded plug (1).
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3. Remove threaded plug (2).
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4. Remove cover (3).
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5. Install Tooling (B).
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6. Install Tooling (C) to Tooling (B).
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7. Use a hoist to install the transmission on the test bench. The weight of the transmission is 1588 kg (3500 lb).
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8. Install Tooling (D) to the input yoke.
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9. Install Tooling (E) on Tooling (D).

   Note: Tooling (E) will adapt to the small drive shaft, install Tooling (F) on Tooling (D).

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10. Align the transmission with the input drive shaft.
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11. Install the drive shaft guard.
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12. Tighten all four castle nuts and jack bolts.

13. Connect the input drive shaft to Tooling (E).
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14. Install Tooling (G) to the input and output ends of the transmission.
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    Illustration 17	g02726419

15. Install Tooling (H).
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16. Use a hoist to install Tooling (J). The weight of Tooling (J) is 121 kg (267 lb).

    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.

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17. Loosen Allen Fitting (4).
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18. Use bolt (5) to adjust Tooling (J) inward until Tooling (J) contacts the carrier. Tooling (J) will slide into Tooling (H).
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19. Tighten the collet on Tooling (J) to connect Tooling (J) to Tooling (H).

20. Adjust Tooling (J) to provide a 3 - 4 mm (0.12 - 0.16 inch) gap spacing between Tooling (J) and the carrier.

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

21. Tighten Allen Fitting (4).
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22. Remove cover (6).
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23. Remove covers (7), (8), and (9).
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24. Install Tooling (K), (L), and (M).
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    Illustration 25	g02726537
    (10) Transmission Supply Oil Out

25. Connect hose assembly (10) from the pressurized flow meter to Tooling (M) to the inlet of the "Number 2" flow meter.
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    Illustration 26	g02726663
    Inlet for the Transmission Lubrication Oil

26. Connect hose assembly (11) from the No. 2 flow meter outlet to Tooling (L).

    Note: The No.2 flow meter will measure the lube flow.

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    Illustration 27	g02726696
    Transmission Supply Oil In

27. Connect hose assembly (12) from the pressurized flow meter on the test bench to Tooling (K).
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    Illustration 28	g02726703

28. Connect hose assembly (13) from the auxiliary oil supply at the test bench to Tooling (J). Maintain an oil pressure of 275 kPa (40 psi).
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    Illustration 29	g02726706
    (14) Main Relief Pressure

29. Connect a pressure gauge to test port (14).
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    (15) Input Transfer Gear Lube Pressure

30. Connect a pressure gauge to test port (15).
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    (16) Lubrication Pressure

31. Connect a pressure gauge to test port (16).
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    Illustration 32	g02726741
    (17) No. 1 Clutch Pressure (18) No. 2 Clutch Pressure (19) No. 3 Clutch Pressure (20) No. 4 Clutch Pressure (21) No. 7 Clutch Pressure (22) No. 5 Clutch Pressure (23) No. 6 Clutch Pressure

32. Connect a pressure gauge to each of the clutch pressure taps (17), (18), (19), (20), (21), (22), and (23).
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    Illustration 33	g02726760
    Tooling (N)

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33. Connect Tooling (N) to a power source. Refer to Tool Operating Manual, NEHS0996 for the correct operating instructions.

    Note: Make sure that the transmission is secured to the test bench. Tighten all bolts to the proper torque.

Test Procedure

TA3 Navigation

1. Select “Off-Highway Trucks”.

2. Select “777G-24V”.

Harness Test

1. Make sure that the harness is properly connected.

2. Use Tooling (N) to perform the harness test.

3. Record the values in Table 6.

   Note: Do not continue testing until Harness Test passes.

Start Checks

Note: Refer to Testing and Adjusting, KENR9927-00, "777G 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 during the test.

2. Adjust the input flow to 170 ± 4 L/min (45 ± 1 US gpm).
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   Illustration 35	g02720621

3. With the transmission in the NEUTRAL position, rotate the input shaft in a counterclockwise direction. Adjust the input rotation to 700 ± 30 rpm.

   Note: The direction is determined as you face the drive motor of the test bench.

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

5. 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

6. Check for lockup or excessive drag in all speed ranges.

7. Stop the input rotation.

Lube Check

1. Adjust the lube flow to 151 ± 4 L/min (40 ± 1 US gpm).

2. Adjust the input rotation to 1925 ± 10 rpm.

3. Shift the transmission to the FORWARD 2 position.

4. Record the lubrication pressure in Table 7.

5. The lubrication pressure must be 62 ± 14 kPa (9 ± 2 psi).

Pressure Check (Low Idle)

1. Adjust the input flow to 87 ± 4 L/min (23 ± 1 US gpm).

2. Adjust the input rotation to 700 ± 10 rpm.

3. Shift the transmission through ranges REVERSE, NEUTRAL, FORWARD 1, FORWARD 2, FORWARD 3, FORWARD 4, FORWARD 5, FORWARD 6, and FORWARD 7.

   Note: Always shift the transmission back to NEUTRAL when shifting between FORWARD and REVERSE.

4. Record the clutch pressure for each range in Table 9.

5. Verify that the clutch pressures match the values in Table 8.

Pressure Check (High Idle)

1. Adjust the input flow to 170 ± 4 L/min (45 ± 1 US gpm).

2. Adjust the input rotation to 1925 ± 10 rpm.

3. Shift the transmission through ranges REVERSE, NEUTRAL, FORWARD 1, FORWARD 2, FORWARD 3, FORWARD 4, FORWARD 5, FORWARD 6, and FORWARD 7.

   Note: Always shift the transmission back to NEUTRAL when shifting between FORWARD and REVERSE.

   Note: Return to low idle rpm before shifting between gears.

4. Record the clutch pressure for each range in Table 11.

5. Verify that the clutch pressures match the values in Table 10.

Clutch Leakage Check

1. Adjust the input flow to 170 ± 4 L/min (45 ± 1 US gpm). Maintain this flow during the leakage check.

2. Shift the transmission to the NEUTRAL position.

3. Adjust the input rotation to 1925 ± 10 rpm.

4. Record the supply pressure in Table 13. The correct supply pressure is 2965 ± 35 kPa (430 ± 5 psi).

5. Record the input flow in Table 13.

6. Record the cooler flow in Table 13.

7. The leakage is obtained by subtracting the cooler flow from the input flow.

8. Record the calculation in Table 13.

9. Adjust the input rotation to 800 ± 10 rpm.

10. Shift the transmission through positions FORWARD 1, FORWARD 2, FORWARD 3, FORWARD 4, FORWARD 5, FORWARD 6, FORWARD 7, and REVERSE. Repeat Steps 2 through 9 for each gear range. Adjust the input rotation to 800 ± 30 rpm for all shifts.

    Note: Always shift the transmission back to NEUTRAL when shifting between FORWARD and REVERSE.

11. Verify that the clutch leakages match the values in Table 12.

    Note: Subtract the clutches for the gears called out, eliminating the common clutch.
    EXAMPLE:
    F2 uses CL1 and CL 6
    F1 uses CL 2 and CL 6
    F2 - F1 (CL 1,6 - CL 2,6)
    (eliminate common clutch: CL 6) = CL 1 - CL 2

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 14.

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

Transmission Bench Test Data Sheet

Harness Test

Lube Check

Pressure Check (Low Idle)

Pressure Check (High Idle)

Clutch Leakage Check

Note: Subtract the clutches for the gears called out, eliminating the common clutch.
EXAMPLE:
F2 uses CL1 and CL 6
F1 uses CL 2 and CL 6
F2 - F1 (CL 1,6 - CL 2,6)
(eliminate common clutch: CL 6) = CL 1 - CL 2

Contamination Control