GM Service Manual Online
For 1990-2009 cars only

As vehicle speed increases, the governor allows more oil to pass through, to act against the spring at the 2-3 shift valve. This allows the second clutch oil at the 23 shift valve to be released and pass through the valve as third clutch oil, directed to the third clutch piston to apply third clutch. At the same time, third clutch oil is directed to the 3-2 control valve, acting against the spring and modulator oil, cutting off modulator oil pressure to the 2-3 shift control valve. Third control oil also is directed to the Reverse and Low control valve and passes through the valve as servo release oil to the low speed downshift timing valve. The low speed downshift timing valve is held open against the spring by increased modulator oil pressure. The oil passes through the valve and is directed to the top of the low band servo, to act with the servo piston spring and force the servo piston downward, releasing the low band.

Servo release oil is also directed from near the low reverse control valve through an orifice to the converter clutch control valve and the solenoid area. Oil will bleed out through the solenoid until the governor pressure (and vehicle speed) closes the governor switch. The solenoid is then energized to close the bleed and oil pressure can now move the converter clutch valve to apply the TCC.

Summary

The second clutch is on, the third clutch is on, the band is released. The transmission is in Drive Range - Third Gear, and as speed increases the TCC is applied.

Drive Range, Third Gear


Object Number: 261325  Size: FS
Case Passages

Object Number: 261325  Size: FS