120M Series 2, 12M Series 2, 140M Series 2 and 160M Series 2 Motor Graders All Wheel Drive Electronic Control System Caterpillar

Illustration 1	g03527872
(A) AWD Pump Location

The AWD Pump is serviceable through rear, right side access door.

Illustration 2	g03524743
(1) Rear Piston Pump (Right Side) (2) Forward Piston Pump (Left Side) (3) Left Side Pump Control Valve Group

Illustration 3	g01620345
Section A-A (4) Screw (reverse direction) (5) Nut (6) Plug (7) Plug (8) Screw (forward direction) (9) Nut

1. Shut off the engine.

Left Side AWD Adjust Procedure

Forward Direction

1. Remove nut (9) .

2. Turn screw (8) clockwise until screw (8) is in contact with the control piston.

3. Measure the distance from the top of screw (8) to the top of plug (7) .

4. Screw (8) should be turned in the counterclockwise direction 13 turns. Measure the distance from the top of screw (8) to the top of plug (7). Add the value that was found in Step 3 plus the value that was found in this step. This value should be 16.2 mm (0.64 inch).

5. Install nut (9). Torque nut (9) to 35 N·m (26 lb ft). After nut (9) has been torqued, verify that the distance from the top of screw (8) to the top of plug (7) is the same distance that was found in Step 4.

Reverse Direction

1. Remove nut (5) .

2. Turn screw (4) clockwise until screw (4) is in contact with the control piston.

3. Measure the distance from the top of screw (4) to the top of plug (6) .

4. Screw (4) should be turned in the counterclockwise direction 13 turns. Measure the distance from the top of screw (4) to the top of plug (6). Add the value that was found in Step 3 plus the value that was found in this step. This value should be 16.2 mm (0.64 inch).

5. Install nut (5). Torque nut (5) to 35 N·m (26 lb ft). After nut (5) has been torqued, verify that the distance from the top of screw (4) to the top of plug (6) is the same distance that was found in Step 4.

Verification of the Left Side Pump Adjustments

The following steps will allow the technician to verify that the initial setting for the pump has been made correctly.

1. Start the machine.

2. Set the engine speed to 1600 ± 50 RPM.

3. Open Caterpillar Electronic Technician (Cat^® ET). Select "AWD ECM". Navigate to the "Override" screen.

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Illustration 4	g03525382
Left Front Drive Pump Forward Control Solenoid Current Percentage Override

4. Verify that the AWD "Left Front Speed Ratio" reads zero for the left side prior to applying any overrides.

   Reference If the "Left Front Speed Ratio" (A) is not zero, refer to the AWD ECM Testing and Adjusting, "Piston Pump Neutral - Test and Adjust" for more information.

5. Override the "Left Front Drive Pump Forward Control Solenoid Current Percentage Override" command to 100 percent. Record the "Left Front Speed Ratio". This ratio should be between 0.700 and 0.745.

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Illustration 5	g03526696
Left Front Drive Motor Solenoid Current Percentage Override

6. Override the "Left Front Drive Motor Solenoid Current Percentage Override" command to 100 percent. Record the "Left Front Speed Ratio". This ratio should be between 2.41 and 2.64.

7. Disable all overrides.

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Illustration 6	g03526776
Left Front Drive Pump Reverse Control Solenoid Current Percentage Override

8. Override the "Left Front Drive Pump Reverse Control Solenoid Current Percentage Override" command to 100 percent. Record the "Left Front Speed Ratio". This ratio should be between − 0.700 and − 0.745.

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Illustration 7	g03526778
Left Front Drive Motor Solenoid Current Percentage Override

9. Override the "Left Front Drive Motor Solenoid Current Percentage Override" command to 100 percent. Record the "Left Front Speed Ratio". This ratio should be between − 2.41 and − 2.64.

10. Disable all overrides.

11. The values that were recorded in Step 5 through Step 9 should be within 0.03.

    Note: The values may not be within the acceptable range for the ratios for the pump at this time and will be corrected in Step 13.

12. If the values are not within 0.03, perform the following:

    1. Replace the Pump control valve group.

    2. Replace the pump.

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Illustration 8	g01361592
(10) Adjustment screw for maximum motor displacement (11) Adjustment screw for minimum motor displacement

Note: Decreasing the displacement of the motor will increase the ratio. Increasing the displacement of the motor will decrease the ratio.

13. Adjust the maximum displacement of the motor until the "Forward Pump Ratio" is between 0.700 and 0.745. Adjust the maximum displacement of the motor until the "Reverse Pump Ratio" is between − 0.700 and − 0.745. Perform the following step to adjust the maximum displacement of the motor:

    1. To decrease the maximum displacement of the motor, turn screw (10) clockwise. This adjustment will increase the "Forward Pump Ratio" and the "Reverse Pump Ratio" by approximately 0.06 per revolution.

    2. To increase maximum displacement for the motor, turn screw (10) counterclockwise. This adjustment will decrease the "Forward Pump Ratio" and the "Reverse Pump Ration" by approximately 0.06 per revolution.

    3. If the ratios cannot be obtained, replace the motor.

14. Adjust the minimum displacement of the motor until the "Forward Motor Ratio" is between 2.410 and 2.640. Adjust the minimum displacement of the motor until the "Reverse Motor Ratio" is between − 2.410 and − 2.640. Perform the following step to adjust the maximum displacement of the motor:

    1. To decrease the minimum displacement for the motor, turn screw (11) counterclockwise. This adjustment will increase the "Forward Motor Ratio" and the "Reverse Motor Ratio" by approximately 0.40 per revolution.

    2. To increase the minimum displacement for the motor, turn screw (11) clockwise. This adjustment will increase the "Forward Motor Ratio" and the "Reverse Motor Ratio" by approximately 0.40 per revolution.

15. Perform a calibration of the AWD Pump and the AWD Motor by using Cat^® ET.

Right Side AWD Adjust Procedure

Illustration 9	g03527036
(1) Rear Piston Pump (Right Side) (12) Right Side Pump Control Valve Group

Illustration 10	g01620312
Section B-B (13) Screw (Reverse Direction) (14) Nut (15) Plug (16) Plug (17) Screw (Forward Direction) (18) Nut

Forward Direction

1. Remove nut (18) .

2. Turn screw (17) clockwise until screw (17) is in contact with the control piston.

3. Measure the distance from the top of screw (17) to the top of plug (16) .

4. Screw (17) should be turned in the counterclockwise direction 13 turns. Measure the distance from the top of screw (17) to the top of plug (16). Add the value that was found in Step 3 plus the value that was found in this step. This value should be 16.2 mm (0.64 inch).

5. Install nut (18). Torque nut (18) to 35 N·m (26 lb ft). After nut (18) has been torqued, verify that the distance from the top of screw (17) to the top of plug (16) is the same distance that was found in Step 4.

Reverse Direction

1. Remove nut (14) .

2. Turn screw (13) clockwise until screw (13) is in contact with the control piston.

3. Measure the distance from the top of screw (13) to the top of plug (15) .

4. Screw (13) should be turned in the counterclockwise direction 13 turns. Measure the distance from the top of screw (13) to the top of plug (15). Add the value that was found in Step 3 plus the value that was found in this step. This value should be 16.2 mm (0.64 inch).

5. Install nut (14). Torque nut (14) to 35 N·m (26 lb ft). After nut (14) has been torqued, verify that the distance from the top of screw (13) to the top of plug (15) is the same distance that was found in Step 4.

Verification of the Right Side Pump Adjustments

The following steps will allow the technician to verify that the initial setting for the pump has been made correctly.

1. Start the machine.

2. Set the engine speed to 1600 ± 50 RPM.

3. Open Cat^® ET. Select "AWD ECM". Navigate to the "Override" screen.

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Illustration 11	g03527096
Right Front Drive Pump Forward Control Solenoid Current Percentage Override

4. Verify that the AWD "Right Front Speed Ratio" reads zero for the left side prior to applying any overrides.

   Reference Verify that the AWD "Right Front Speed Ratio" reads zero for the left side prior to applying any overrides.

5. Override the "Right Front Drive Pump Forward Control Solenoid Current Percentage Override" command to 100 percent. Record the "Right Front Speed Ratio". This ratio should be between 0.700 and 0.745.

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Illustration 12	g03527077
Right Front Drive Motor Solenoid Current Percentage Override

6. Override the "Right Front Drive Motor Solenoid Current Percentage Override" command to 100 percent. Record the "Right Front Speed Ratio". This ratio should be between 2.41 and 2.64.

7. Disable all overrides.

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Illustration 13	g03527116
Right Front Drive Pump Reverse Control Solenoid Current Percentage Override

8. Override the "Right Front Drive Pump Reverse Control Solenoid Current Percentage Override" command to 100 percent. Record the "Right Front Speed Ratio". This ratio should be between − 0.700 and − 0.745.

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Illustration 14	g03527077
Right Front Drive Motor Solenoid Current Percentage Override

9. Override the "Right Front Drive Motor Solenoid Current Percentage Override" command to 100 percent. Record the "Right Front Speed Ratio". This ratio should be between − 2.41 and − 2.64.

10. Disable all overrides.

11. The values that were recorded in Step 5 through Step 9 should be within 0.03.

    Note: The values may not be within the acceptable range for the ratios for the pump at this time and will be corrected in Step 13.

12. If the values are not within 0.03, perform the following:

    1. Replace the Pump control valve group.

    2. Replace the pump.

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Illustration 15	g01361649
(19) Adjustment screw for minimum motor displacement (20) Adjustment screw for maximum motor displacement

Note: Decreasing the displacement of the motor will increase the ratio. Increasing the displacement of the motor will decrease the ratio.

13. Adjust the maximum displacement of the motor until the "Forward Pump Ratio" is between 0.700 and 0.745. Adjust the maximum displacement of the motor until the "Reverse Pump Ratio" is between − 0.700 and − 0.745. Perform the following step to adjust the maximum displacement of the motor:

    1. To decrease the maximum displacement of the motor, turn screw (20) clockwise. This adjustment will increase the "Forward Pump Ratio" and the "Reverse Pump Ratio" by approximately 0.06 per revolution.

    2. To increase maximum displacement for the motor, turn screw (20) counterclockwise. This adjustment will decrease the "Forward Pump Ratio" and the "Reverse Pump Ration" by approximately 0.06 per revolution.

    3. If the ratios cannot be obtained, replace the motor.

14. Adjust the minimum displacement of the motor until the "Forward Motor Ratio" is between 2.410 and 2.640. Adjust the minimum displacement of the motor until the "Reverse Motor Ratio" is between − 2.410 and − 2.640. Perform the following step to adjust the maximum displacement of the motor:

    1. To decrease the minimum displacement for the motor, turn screw (19) counterclockwise. This adjustment will increase the "Forward Motor Ratio" and the "Reverse Motor Ratio" by approximately 0.40 per revolution.

    2. To increase the minimum displacement for the motor, turn screw (19) clockwise. This adjustment will increase the "Forward Motor Ratio" and the "Reverse Motor Ratio" by approximately 0.40 per revolution.

15. Perform a calibration of the AWD Pump and the AWD Motor by using Cat^® ET.