TUBE 3062343 - Caterpillar

Illustration 1 g03390725
Hydraulic System Schematic (1) Transmission oil filter (2) Transmission hydraulic control relief valve (3) Torque converter (4) Transmission oil pump (5) Torque converter outlet relief valve (6) Torque converter inlet relief valve (7) Modulating valve for the lockup clutch (8) Modulating valve for the impeller clutch (9) Transmission oil cooler (10) Modulating valve for number 1 clutch (11) Modulating valve for number 4 clutch (12) Modulating valve for number 2 clutch (13) Modulating valve for number 5 clutch (14) Modulating valve for number 3 clutch (15) Modulating valve for number 6 clutch (16) Suction screen and magnet (17) Oil sump (A) Pressure tap for pump pressure (AA) Flow to bearing lube (transmission) (BB) Flow to input transfer lube (CC) Flow to output transfer lube (DD) Flow to pump drive Starting the Engine with the Transmission in the NEUTRAL position
When the engine is started, the transmission oil pump (4) pulls oil from oil sump (17). The oil flows through the suction screen and magnet (16). Transmission oil pump (4) sends pressurized oil through transmission oil filter (1). The pressurized oil is directed in two different directions after the oil exits transmission oil filter (1). The oil can take one path to the modulating valve for the lockup clutch (7) and the modulating valve for the impeller clutch (8). The other path splits into two directions. One direction flows to relief valve (2) and the other direction flows to clutch solenoid modulating valves (10-15). "Number 3" modulating valve (12) is energized because the transmission is in neutral. None of the remaining clutch solenoid modulating valves (10), (11), (13), (14) and (15) provide oil to the transmission clutches. The pressurized oil leakage drains to oil sump (17) .Transmission hydraulic control relief valve (2) routes the torque converter inlet oil to torque converter (3). Torque converter outlet oil flows through torque converter outlet relief valve (5) to oil cooler (9). After the oil cools, the oil drains to transmission oil sump (17) .Torque converter inlet relief valve (6) limits torque converter inlet oil pressure to a maximum of 900 70 kPa (130 10 psi). Torque converter inlet relief valve (3) is located inside transmission hydraulic control relief valve (2). Shifting the Transmission from the NEUTRAL position to the FIRST SPEED FORWARD position
The transmission electronic control module (ECM) modulates the electrical current that is sent to the selected clutch solenoid modulating valves. The oil pressure to the transmission clutch is controlled by modulating the electrical current to the clutch solenoid modulating valves.When the transmission direction control switch and the transmission speed switch are shifted to the FIRST SPEED FORWARD position, both "Number 2" modulating valve (11) and "Number 6" modulating valve (15) are energized."Number 2" modulating valve (11) is electronically modulated when the "Number 2" clutch is filled. "Number 6" modulating valve (15) is electronically modulated when the "Number 6" clutch is filled. When the electrical current is modulated to the full current, the Number 6 clutch and