Operation CHARM: Car repair manuals for everyone.

Park-Engine Running

Park - Engine Running:






PARK-ENGINE RUNNING

CONVERTER CLUTCH - RELEASED
INPUT CLUTCH - APPLIED
INPUT SPRAG - HOLDING

With the selector lever in Park (P) position, oil from the pump is directed to the following:
1. Pressure Regulator Valve: Regulates pump output based on modulator, Drive 1, Reverse, and pressure regulator valve spring pressure. When the calibrated line pressure is obtained, the pressure regulator valve directs oil into the converter feed passage.
2. Converter Clutch Apply Valve: Held to the right by line pressure and directs converter feed pressure to the release side of the converter clutch.
3. Converter Clutch Regulator Valve: Regulates converter feed pressure int0 converter apply pressure which is used to apply the converter clutch in other ranges.
4. Modulator Valve: Controlled by the modulator, it regulates modulator pressure inversely to engine vacuum. Modulator pressure controls line pressure and accumulator pressure for proper shift feel.
5. Manual Valve: Controlled by the shift selector in Park, the manual valve directs oil to the following:
a. Input Clutch: The input clutch is applied and drives the input sun gear.
b. Reverse Boost Valve: Works with modulator pressure to boost line pressure from a minimum of about 449 kPa (65 psi.) to a maximum of about 1737 kPa (253 psi.) in Park, Reverse, and Neutral.
c. Throttle Valve (T.V.) Limit Valve: Limits the feed to the throttle valve to a maximum of 620 kPa (90 psi.)
d. Throttle Valve and Plunger: Regulates T.V. pressure in proportion to accelerator pedal movement from 0 kPa (0 psi.) to 620 kPa (90 psi.). T.V. pressure pushes against governor pressure on the 1-2, 2-3 and 3-4 shift valves to change shift points according to road demands.

6. 2-3 Shift Valve: Directs line pressure through the 3-4 shift valve to the input clutch.

SUMMARY
The converter clutch is released; the input clutch is applied; the input sprag is driving the input sun gear; the modulator and T.V. circuits are filled, and the parking pawl is engaged.