992G Wheel Loader and 854G Wheel Dozer Power Train Caterpillar

Illustration 1	g00488441
Hydraulic System Schematic (1) Priority valve. (2) Lockup clutch solenoid valve (if equipped). (3) Impeller clutch solenoid valve. (4) Transmission hydraulic controls. (5) Oil filter. (6) Oil filter. (7) Torque converter. (8) Lockup clutch (if equipped). (9) Impeller clutch. (10) Oil pump. (11) Torque converter outlet relief valve. (12) Flow control orifice. (13) Magnetic screen. (14) Oil cooler. (15) Reservoir in output transfer gear case. (16) Outlet line from oil cooler to planetary lubrication. (A) Oil pump output pressure tap P1. (B) Pressure tap for oil pump. (C) Pressure tap for lockup clutch (if equipped). (D) Torque converter inlet pressure tap P3. (E) Pressure tap for oil pump. (F) Pressure tap for impeller clutch. (G) Lubrication pressure tap. (H) Torque converter outlet pressure tap.

Note: Reduced rimpull is a feature of the 992G Wheel Loader. The 854G Wheel Tractor is not equipped with this feature.

Illustration 2	g00107979
992G Wheel Loader Torque Converter Cover (C) Pressure tap for lockup clutch (if equipped). (F) Pressure tap for impeller clutch.

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine.

1. Park the machine on a smooth level surface.

2. Shift the STIC transmission direction control to the NEUTRAL position.

3. Lower the bucket and/or the attachment to the ground. Lower the blade and/or the attachment to the ground.

4. Engage the parking brake.

5. Place blocks in front of the wheels and behind the wheels.

6. Install the steering frame lock.

7. Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.

Note: All tests and all adjustments must be made while the transmission oil is at normal operating temperature.

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The drive shaft rotates between the torque converter and the transmission whenever the engine is running. Contact with the rotating shaft can result in personal injury or death. The rotating shaft is located under the implement and steering pumps. Do not allow personnel into the pump bay area behind the cab when the engine is running.

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before moving the machine to perform the test that follows.

Note: The default settings for reduced rimpull can be changed in the field. The power train control must be set to the default settings for reduced rimpull before a test of the four reduced rimpull settings can be performed.

ReferenceRefer to the Service Manual module for Systems Operation, Testing and Adjusting, SENR1372, "Power Train Electronic Control System" for the procedure for programming the set points for reduced rimpull. The following values are the default settings for reduced rimpull: 35 percent, 50 percent, 65 percent and 80 percent.

1. Install a hose and a 4130 kPa (600 psi) pressure gauge on pressure tap (F) .

2. Engage the parking brake and start the engine.

3. Place the transmission in first speed forward.

4. Move the reduced/maximum rimpull switch to the REDUCED position. The indicator light for reduced rimpull must come on.

5. Move the reduced rimpull selection control to the MINIMUM position (small dot).

6. Increase the engine speed to high idle and observe the pressure reading on the gauge. Record the gauge reading.

7. With the engine at high idle, move the reduced rimpull selection control to each of the remaining positions. Record the pressure reading at each of the control positions. Refer to Table 2 below for the correct pressures.