Forward Clutch Hydraulic Circuits
When the forward (1, 2, 3, 4) clutch is applied in 1st (above 5 km/h [3 MPH]), 2nd, 3rd and 4th gears, LINE pressure from the pump is directed to the multiplex shift valve by the manual valve through the DRIVE 1 hydraulic circuit. The multiplex shift valve supplies the forward (1, 2, 3, 4) clutch regulator valve with pressure through the DRIVE 2, CB26FD/CB1234FD and CB1234 SUP hydraulic circuits. The forward (1, 2, 3, 4) clutch regulator valve directs regulated pressure to the forward (1, 2, 3, 4) clutch through the CB1234 hydraulic circuit.
When the forward (1, 2, 3, 4) clutch is applied in LOW position and 1st gear (below 5 km/h [3 MPH]), LINE pressure from the pump is directed to the multiplex shift valve by the manual valve through the DRIVE 1 hydraulic circuit. The multiplex shift valve directs the pressure to the multiplex manual valve through the REV DRIVE B circuit. The multiplex manual valve directs the REV DRIVE B pressure to the forward (1, 2, 3, 4) clutch regulator valve through the DRIVE B, CB26FD/CB1234FD and CB1234 SUP circuits. SSA supplies varying solenoid pressure to the CB1234 clutch regulator and boost valves. As the CB1234 clutch regulator valve moves, it supplies the forward (1, 2, 3, 4) clutch and CB1234 boost valve with regulated line pressure through the CB1234 circuit. The CB1234 boost valve directs the regulated line pressure to the opposite side of the regulator valve through the CB1234 FDBK circuit for gradual forward (1, 2, 3, 4) clutch engagement.
When the forward (1, 2, 3, 4) clutch is released in 5th and 6th gears, DRIVE 2 pressure is directed to the forward (1, 2, 3, 4) clutch regulator valve. Solenoid pressure is not applied to the forward (1, 2, 3, 4) clutch regulator valve and the regulator valve blocks the DRIVE 2 circuit in this position.