Drive Range - Manual Third (From Overdrive Range Fourth Gear)

Drive Range - Manual Third (From Overdrive Range Fourth Gear):

DRIVE RANGE - MANUAL THIRD

(From Overdrive Range Fourth Gear)

When the gear selector lever is moved to the Drive Range (3) position, the manual valve also moves and allows line pressure to enter the D321 fluid circuit. The torque converter clutch releases in the same manner as previously described in Overdrive Range Fourth gear, but may re-apply when the appropriate operating conditions of the vehicle have been met.

COAST CLUTCH APPLIES

Manual Valve: Mechanically moved through the gear selector lever, it allows line pressure to enter the D321 fluid circuit and PRND4 fluid to exhaust at the valve. D321 fluid is then routed to the spring end of the 3-4 shift valve.

3-4 Shift Valve: Held in the downshifted position by spring force and D321 fluid pressure, it allows D321 fluid to pass through the valve and enter the coast clutch feed circuit. Coast clutch feed is then routed to checkball #9.

#9 Checkball (Coast C1. Feed/Orificed Coast C1. Fd.): Located in the valve body, it is un-seated by coast clutch feed and routes fluid through orifice #7 where it enters the coast clutch circuit. Coast clutch fluid is then routed to the 2-3 shift valve.

2-3 Shift Valve: Held in the upshifted position by high solenoid "B" fluid pressure, it allows coast clutch fluid to pass through the valve. Coast clutch fluid is then routed to the coast clutch piston and applies the clutch.

Pressure Switch: PRND4 fluid at the PRND4 indicator switch exhausts to open its electrical circuit to the PCM. The open circuit is a signal to the PCM that Manual Third gear range was selected by the operator of the vehicle.

4TH BAND RELEASES

Solenoid "A": De-energizes, allowing solenoid "A" fluid pressure (acting on the end of the 3-4 shift valve) to exhaust through the solenoid. With low fluid pressure in the solenoid "A" fluid circuit, the 3-4 shift valve is forced to move from spring force acting on the opposite end of the valve.

4th Servo Assembly: Spring force actuates the 4th servo piston and returns it to its band released position. This movement forces 4th band fluid from the other side of the piston is forced back through its circuit to the 1-2 shift valve.

1-2 Shift Valve: Held in the upshifted position by spring force and solenoid "B" pressure, 4th band fluid is routed back through the valve and into the 4th band feed circuit. 4th band feed is then routed to the 3-4 shift valve.

3-4 Shift Valve: Held in the downshifted position by spring force and D321 fluid, 4th band fluid from the 1-2 shift valve is routed through the valve into the orificed D21Y fluid passage. Orificed D21Y fluid is then routed through the 2-3 shift valve where it exhausts.