KIT-COMPENSATOR 5249577 - Caterpillar

Introduction
The (four speed) PG145 Transmission provides 4 forward gears and 3 reverse gears.The (six speed) PG145 Transmission provides 6 forward gears and 3 reverse gears.There are 6 individual clutch packs on 3 transmission shafts. Each clutch pack is controlled by a corresponding solenoid valve. The transmission electronic control module (ECM) controls the solenoid valves. The solenoid valves control oil flow to the clutch packs. The transmission input shaft receives engine power through a torque converter. The transmission delivers output power through an attached transfer case.The transmission hydraulic system has the following main components:
Sump
Suction Screen
Charge Pump
Oil Filter
Relief Valve (Charge Pressure)
Relief Valve (Torque Converter Inlet)
Solenoid ValvesSump
The sump is the reservoir for transmission oil.Suction Screen
The suction screen removes potential large particles from the transmission oil that is picked up by the charge pump.Charge Pump
The charge pump provides pressurized oil to the transmission hydraulic system. The oil flow from this pump is continuous and the pressure is constant after the engine is started.Oil Filter
The oil filter removes contaminants from the transmission oil.Relief Valve (Charge Pressure)
The relief valve (charge pressure) regulates the main transmission oil pressure.Relief Valve (Torque Converter Inlet)
The relief valve (torque converter inlet) regulates the torque converter inlet oil pressure.Solenoid Valves
The transmission is equipped with 6 solenoid valves. The solenoid valves are controlled by the Transmission ECM. 6 solenoid valves control the flow of oil to the 6 corresponding clutches.Transmission Hydraulic System
The transmission hydraulic system provides a consistent flow of pressurized oil to the transmission. Oil is drawn from the sump, through the suction screen, to the charge pump. The charge pump is the source of pressurized oil flow. Pressure is regulated by the charge pressure relief valve. From the charge pressure relief valve, oil flows to the clutch circuit and also to the torque converter. The torque converter inlet relief valve setting is lower than charge oil pressure. Oil flows through the torque converter to the transmission oil cooler. After being cooled, the oil returns to the transmission to lubricate and cool the clutches and bearings. The transmission contains 6 clutch assemblies. Each clutch receives oil when the corresponding solenoid valve is commanded open by the transmission ECM. Clutches are engaged in certain combinations to provide the different forward and reverse gear ratios.Transmission Electrical System
The transmission electrical system provides controls for the transmission hydraulic system. The transmission electrical system includes solenoid valves for the clutches, and an output shaft speed sensor. The output shaft speed sensor provides an input signal to an ECM. The ECM also receives operator control inputs for speed and direction. The ECM sends an electrical signal to the appropriate solenoid valves, to allow the required clutches to receive pressurized oil.