GM Service Manual Online
For 1990-2009 cars only

No 2-3 Shift

Checks

Cause

Control Valve Assembly

    â€¢ Stuck 2-3 shift valve
    â€¢ Stuck 3-2 manual downshift valve

Channel Plate Gasket

Mispositioned or damaged

Driven Sprocket Support

Blocked Third clutch passage

Input Housing and Shaft Assembly

    â€¢ Damaged seals
    â€¢ Blocked oil passages

Third Clutch Assembly

    â€¢ Burned clutch plates
    â€¢ Damaged piston or seals
    â€¢ Damaged checkball assembly in the piston

Third Roller Clutch Assembly

    â€¢ Damaged cage
    â€¢ Rollers out of the cage
    â€¢ Damaged springs
    â€¢ Misassembled input sun gear shaft
    â€¢ No third gear in Manual Lo
    â€¢ No engine braking in Manual Lo