Overdrive Clutch Assembly
Overdrive (O/D) (4, 5, 6) Clutch Exploded View
| Item | Description |
|---|---|
| 1 | Direct/overdrive clutch hub assembly |
| 2 | Overdrive clutch piston inner seal |
| 3 | Input shaft |
| 4 | Overdrive clutch piston outer seals |
| 5 | Overdrive clutch piston |
| 6 | Overdrive clutch piston return spring |
| 7 | Overdrive clutch balance piston |
| 8 | Overdrive clutch balance piston snap ring |
| 9 | Overdrive (4, 5, 6) clutch assembly |
| 10 | Overdrive clutch pressure plate |
| 11 | Overdrive clutch snap ring |
| 12 | Overdrive clutch hub |
| 13 | Rear planetary carrier |
Overdrive (O/D) (4, 5, 6) Clutch Cutaway View
Overdrive Clutch Mechanical Operation
The overdrive clutch is a drive clutch that transfers power from the direct/overdrive clutch hub assembly to the rear planetary carrier. The overdrive clutch is applied in 4th, 5th and 6th gears.
Hydraulic pressure from the regulator valve in the valve body pushes the overdrive clutch piston against the overdrive clutch pack to apply the clutch. The input shaft and direct/overdrive clutch hub assembly transfers torque to the rear planetary carrier as a result of the clutch being applied.
Overdrive (4, 5, 6) Clutch Hydraulic Circuits (Applied in 4th, 5th and 6th gear)
Line pressure is supplied to the low reverse/456 regulator valve by the pump in every gear and manual lever position. To apply the low/reverse clutch, SSD supplies varying solenoid pressure to the low reverse/456 regulator and latch valves. As the regulator valve moves, it supplies the clutch control bypass valve and low reverse/456 latch valve with regulated line pressure through the CBR1/C456 circuit. The low reverse/456 latch valve directs the regulated line pressure to the opposite side of the low reverse/456 regulator valve through the CBR1/C456 FDBK circuit for gradual overdrive (4, 5, 6) clutch engagement.
To apply the overdrive (4, 5, 6) clutch, the position of the clutch control bypass valve allows the regulated line pressure in the CBR1/C456 circuit to supply the C456 circuit, applying the overdrive (4, 5, 6) clutch. Clutch control bypass valve latch pressure is supplied by the C456 circuit. The overdrive (4, 5, 6) clutch is applied in 4th, 5th and 6th gears.
Overdrive (4, 5, 6) Clutch Hydraulic Circuits (Released)
When the overdrive (4, 5, 6) clutch is released in 1st gear above 8 km/h (5 mph), 2nd and 3rd gears, solenoid pressure from SSD is removed from the low reverse/456 regulator and latch valves which positions the valves to block line pressure and release the overdrive (4, 5, 6) clutch.
When the overdrive (4, 5, 6) clutch is released in 1st gear above 8 km/h (5 mph), 2nd and 3rd gears, exhaust backfill supplied to the low reverse/456 clutch regulator valve and the clutch control bypass valve by the manual valve through the EXH BF circuit is directed to the low reverses latch valve, low/reverse clutch and overdrive (4, 5, 6) clutch to fill the unused circuits with unpressurized transmission fluid.
When the overdrive (4, 5, 6) clutch is released in PARK, REVERSE, NEUTRAL and 1st gear below 8 km/h (5 mph), the low reverse/456 regulator valve supplies regulated pressure to the clutch control bypass valve through the CBR1/C456 circuit. With ON/OFF SSE in the ON position, the regulated pressure is directed to the low/reverse clutch.
For details on valve body hydraulic circuits and solenoid operation. For additional information, refer to: Transmission Description - System Operation and Component Description .
Overdrive (4, 5, 6) Clutch Fluid Passages