Detent Downshift, Valves in Second Gear. Pontiac Sun Runner - 4WD (Canada) 1998

For 1990-2009 cars

With the selector lever in the Drive position, detent downshifts are possible by fully depressing the accelerator pedal. This causes the mechanical linkage to the detent valve to move the detent valve, cutting off modulator oil to the 3-2 control valve, the 1-2 shift control valve, the 1-2 accumulator valve and the 2-3 shift control valve.

The mechanical linkage holding the detent valve open allows the detent regulated oil to pass into the detent oil passage and is directed to the 2-3 shift control valve, acting against the spring and governor oil pressure. It is also directed to the 3-2 control valve, acting against the spring, allowing detent oil to pass through the valve and act on the end of the 2-3 shift control valve to keep the valve bottomed in its bore against governor oil pressure. Second clutch oil at the 2-3 shift valve is closed off from passing into the third clutch passages by the detent oil pressure holding the 2-3 shift valve bottomed in its bore.

#### Summary

The second is clutch on, the low band is on. The valves are in Second Gear position under detent conditions.

#### Detent Downshift, Valves in Second Gear Position

Case Passages