Part Throttle 3-2 Downshift

A part throttle 3-2 downshift may be obtained below about 50 mph 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 (P.T.) passage. This oil, called part throttle (P.T.) 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 seats the direct clutch exhaust check ball, 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 direct clutch oil. Second oil acting on the servo piston applies the band for a smooth band apply as the direct clutch is released.