Low/Reverse Clutch Assembly

Low/Reverse Clutch Exploded View

Low/Reverse Clutch Cutaway View

Low/Reverse Clutch Mechanical Operation

The low/reverse clutch is a brake clutch that holds the low One-Way Clutch (OWC) which is splined to the rear planetary carrier. The low/reverse clutch is applied in manual LOW, REVERSE and 1st gear up to 8 km/ h (5 mph).

Hydraulic pressure from the regulator valve in the valve body pushes the low/reverse clutch piston against the low/reverse clutch pack to apply the clutch. The rear planetary carrier is held stationary to the transmission case as a result of the clutch being applied.

Low/Reverse Clutch Hydraulic Circuits (Applied in REVERSE)

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, Shift Solenoid D (SSD) supplies varying solenoid pressure to the low reverse/456 regulator and latch valves. As the low reverse/456 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 456 regulator valve through the CBR1/C456 FDBK circuit for gradual low reverse/456 clutch engagement. The low/reverse clutch is applied in PARK, REVERSE, NEUTRAL, 1st gear below 8 km/ h (5 mph) and manual LOW position.

In REVERSE, both solenoid pressure from ON/OFF Shift Solenoid E (SSE) and line pressure from the manual valve in the REVERSE circuit apply pressure to the clutch control bypass valve to position it for low/ reverse clutch application. Regulated line pressure from the CBR1/C456 circuit is directed to the low/ reverse clutch by the clutch control bypass valve through the CBR1 circuit to apply the low/reverse clutch.

Low/Reverse Clutch Hydraulic Circuits (Applied in PARK, NEUTRAL, LOW or 1st gear below 8 km/h [5 mph])

When the low/reverse clutch is applied in PARK, NEUTRAL, LOW or 1st gear below 8 km/h (5 mph), only pressure from ON/OFF Shift Solenoid E (SSE), positions the clutch control bypass valve. Line pressure from the REVERSE circuit is not supplied by the manual valve.

Low/Reverse Clutch Hydraulic Circuits (Released)

When the low/reverse clutch is released in 1st gear above 8 km/h (5 mph), 2nd and 3rd gears, solenoid pressure from Shift Solenoid D (SSD) is removed from the low reverse/456 regulator and latch valves which positions the valves to block line pressure and release the low/reverse clutch. Solenoid pressure from Shift Solenoid E (SSE) is removed from the clutch control bypass valve to position it to apply the overdrive (4, 5, 6) clutch.

When the low/reverse 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 reverse/456 latch valve, low/reverse clutch and overdrive (4, 5, 6) clutch to fill the unused circuits with unpressurized transmission fluid.

When the low/reverse clutch is released in 4th, 5th and 6th gears, the low reverse/456 regulator valve supplies regulated pressure to the clutch control bypass valve through the CBR1/C456 circuit. With ON/ OFF Shift Solenoid E (SSE) in the OFF position, the regulated pressure is directed to the overdrive (4, 5, 6) clutch.

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

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