Part Throttle 3-2 Downshift (Valves In Second Gear Position)

Part Throttle 3-2 Downshift - Valves In Second Gear Position:

PART THROTTLE 3-2 DOWNSHIFT (Valves In Second Gear Position)

CONVERTER CLUTCH - RELEASED
FORWARD CLUTCH - APPLIED
INTERMEDIATE BAND - APPLIED

A part throttle 3-2 downshift can be accomplished below approximately 50 mph (80 km/h) by depressing the accelerator pedal far enough to move the throttle valve (T.V.) plunger to allow shift T.V. oil to enter the part throttle (PT.) passage. This oil, called part throttle (PT.) oil, is then routed to the 2-3 T.V. valve.

Part throttle oil and the 2-3 spring force will close the 2-3 shift valve against governor oil, shutting off RND oil to the direct clutch passage. Exhausting direct clutch oil opens the 3rd clutch pressure switch releasing the [1][2]torque converter clutch, seats the direct clutch exhaust checkball (1), flows through the two orifices, and is exhausted at the 2-3 shift valve. At the same time, direct clutch accumulator oil from the intermediate servo also exhausts through the same route as directed clutch oil. Second oil acting on the servo piston applies the band for a smooth band apply as the direct clutch is released.