Overdrive Range - Third Gear

Overdrive Range - Third Gear:

OVERDRIVE RANGE - THIRD GEAR

As the speed of the vehicle increases, the Powertrain Control Module (PCM) receives input signals from various engine and transaxle sensors. The PCM uses this data to energize solenoid "B" in order to shift the transaxle into third gear at the appropriate time.

THIRD CLUTCH APPLIES

Shift Solenoid "B": Energized (ON) by the PCM, it blocks the exhaust of solenoid "B" fluid to create high pressure in the solenoid "B" passage. High solenoid "B" fluid pressure at the end of the 2-3 shift valve moves the valve into the upshifted position.

2-3 Shift Valve: Held in the upshifted position by high solenoid "B" fluid pressure, it allows drive fluid to pass between two valve lands and enter the 3rd clutch circuit. 3rd clutch fluid is then routed to the 3rd clutch piston and applies the clutch. In addition, 3rd clutch fluid is routed to the following components:

^ Checkball #11

^ 2-3 Accumulator Piston

^ 3rd Clutch Exhaust Valve

^ Torque Converter Clutch (TCC) Solenoid

^ 3-4 Shift Valve

#11 Checkball (3rd Clutch/Orificed 3rd Clutch): Located in the case cover, it is seated by 3rd clutch pressure and routes fluid through orifice #31 where it enters the orificed 3rd clutch circuit. Orificed 3rd clutch fluid is also routed to the 2-3 accumulator valve, the 1-2 & 3-4 accumulator valve and the converter clutch solenoid.

2-3 SHIFT ACCUMULATION

2-3 Accumulator Piston: Actuated by orificed 3rd clutch pressure, it cushions the apply of the 3rd clutch. 2-3 accumulator fluid acting on the spring side of the piston is forced back through its circuit to checkball #10.

#10 Checkball (2-3 Accumulator/Secondary 2-3 Accumulator): Located in the case cover, it is unseated by 2-3 accumulator fluid, allowing fluid to enter the secondary 2-3 accumulator circuit. Secondary 2-3 accumulator fluid is then routed to the 2-3 accumulator valve.

2-3 Accumulator Valve: Biased by spring force and torque signal on one end of the valve, it regulates the exhaust of 2-3 accumulator fluid during a 2-3 shift.

3rd Clutch Exhaust Valve: Shifted against spring force by orificed 3rd clutch fluid pressure, it allows orificed 3rd clutch fluid to enter the 3rd clutch circuit and apply the 3rd clutch.