POWER TRAIN AR 1502008 - Caterpillar

Oil Cooler Inlet Pressure
Check the oil cooler inlet pressure when the transmission oil is cold.1. Install a pressure gauge in test port P3.2. Start the engine and operate at high idle. The pressure gauge should register the value given in the transmission pressures chart.Torque Converter Outlet Pressure
1. Install a pressure gauge in the test port on the directional valve. 2. Stall the torque converter (see later) and note the pressure reading.3. Compare the converter outlet pressure reading with the value given in the transmission pressures chart.4. Shut down the engine, remove the pressure gauge and replace the test port plug.Retarder Outlet Pressure
1. Install a pressure gauge in the test port on the directional valve (see above). Use a length of flexible hose so that the gauge can be taken into the cab.2. Start the engine and drive the truck forward until a speed of about 20 m.p.h. (32 km/h) is reached.3. Slowly apply the retarder and check the pressure reading. The pressure should increase as the retarder application increases to the value given in the transmission pressures chart.Lubrication Pressure
1. Install a pressure gauge in the lubrication test port. 2. Start the engine and operate at high idle. The lubrication pressure will be displayed on the pressure gauge. See the transmission pressures chart.Speed Clutch Pressure Adjustment.
The initial pressure setting of the speed clutches can be adjusted by adding or removing shims(2) from load piston(1). The addition of shims will increase the pressure setting. Lock-Up Clutch Test
1. Install a pressure gauge in the lock up test port. 2. Check that the park brake is applied and that the transmission selector is in neutral.3. Start the engine and increase the engine speed while observing the pressure gauge. If the engine is started from cold allow it to idle for a few moments before increasing speed.4. The gauge should register zero pressure while the clutch is disengaged. The dash indicator should be illuminated at the same time.5. Increase the engine speed until the transmission input speed is high enough to cause lock-up clutch engagement. The pressure gauge should then register the value given in the transmission pressures chart.6. If the gauge does not register pressure check the following: a) Magnetic sensor.b) Speed switch.c) Pressure switchd) Solenoid valve.e) Lock-up clutch control valve.7. If the pressure gauge shows the correct reading but the clutch still fails to engage properly, mechanical damage or wear is indicated.8. If the engine speed is too high when the lock-up clutch engages the speed switch may require adjustment. The clutch is engaged when the gauge registers pressure. The dash indicator should go out at the same time.9. If the lock-up clutch pressure reading is incorrect it will be necessary to adjust the shimming of the lock-up pressure control valve.Lock-Up Pressure Adjustment
The lock-up pressure control valve can be shimmed to provide adjustment of the lock-up clutch pressure. Adding shims (1) will increase the lock-up pressure.
DUAL PUMP HOUSING
1. Shims 2. Retarder StemOne 2U4920 shim (0.75mm thick) will alter the pressure