Forward Clutch Assembly. Description and Operation

Forward (1, 2, 3, 4) Clutch Exploded View

Forward (1, 2, 3, 4) Clutch Sectional View

Forward (1, 2, 3, 4) Clutch Mechanical Operation

The forward clutch is a brake clutch that holds the front sun gear and housing assembly. The forward clutch is applied in 1st, 2nd, 3rd and 4th gears.

Hydraulic pressure from the regulator valve in the valve body pushes the forward clutch piston against the forward clutch pack to apply the clutch. The front sun gear and housing assembly is held stationary to the transmission case as a result of clutch engagement.

Forward (1, 2, 3, 4) Clutch Hydraulic Circuits (Applied in 1st, 2nd, 3rd and 4th Gears)

Line pressure is supplied to the 1234 regulator valve by the manual valve in the DRIVE and LOW positions. To apply the forward (1, 2, 3, 4) clutch, the SSA supplies variable solenoid pressure to the 1234 regulator and latch valves. When the regulator valve moves, it supplies regulated line pressure to the forward (1, 2, 3, 4) clutch and the 1234 check valve through the C1234 circuit. The 1234 check valve directs regulated line pressure to the opposite end of the 1234 regulator valve through the FDBK C1234 circuit for gradual forward (1, 2, 3, 4) clutch apply. The forward (1, 2, 3, 4) clutch is applied in 1st, 2nd, 3rd and 4th gears and in the manual LOW position.

Forward (1, 2, 3, 4) Clutch Hydraulic Circuits (Released)

When the forward (1, 2, 3, 4) clutch is released in 5th and 6th gears, the solenoid pressure from the SSA is removed from the 1234 regulator and check valves, which position the valves to block line pressure and release the forward (1, 2, 3, 4) clutch. When the forward (1, 2, 3, 4) clutch is released in the PARK, REVERSE or NEUTRAL position, line pressure is not supplied to the forward (1, 2, 3, 4) regulator valve.

In the released position, exhaust backfill is routed to the 1234 regulator and check valves by the manual valve through the DP DV circuit. It is directed to the forward (1, 2, 3, 4) clutch to fill unused circuits with unpressurized transmission fluid.

For detailed information on valve body hydraulic circuits and solenoid operation, refer to
For additional information, refer to: Transmission Description - System Operation and Component Description (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Description and Operation).