A part throttle 3-2 downshift can be accomplished below approximately
80 km/h (50 mph). Depress the accumulator pedal as far as necessary
in order to move the throttle valve (TV) plunger. This movement allows
the shift TV oil to enter the part throttle passage. This oil, called
Part Throttle (PT) oil, is then routed to the 2-3 TV valve.
Part Throttle oil and the 2-3 spring force will close the 2-3 shift
valve against governor oil. This shuts off RND oil to the direct clutch passage.
As the direct clutch oil exhausts:
• | The third clutch pressure switch opens releasing the torque converter
clutch |
• | The direct clutch exhaust checkball seats |
• | The oil flows through the two orifices |
• | The oil exhausts at the 2-3 shift valve |
At the same time, the direct clutch accumulator oil from the intermediate
servo also exhausts through the same route as the directed clutch oil. As
the direct clutch is released, second oil acts on the servo piston and
applies the band for a smooth band apply .
Part Throttle, 3-2 Downshift