GM Service Manual Online
For 1990-2009 cars only

No Second Gear, Slips in Second Gear

Checks

Causes

Second Clutch

No apply or slipping

Piston and Seal Assembly (404)

Binding, cracked, or leaking

Clutch Plates (96-99)

Worn friction or broken splines

Snap Ring (406)

Out of position

Spring (405)

Binding

Driven Sprocket Support (95)

Damaged, leaking, porous

Second Clutch Fluid Routing

Fluid leak or restriction

    • Valve Body
    • Gaskets and Spacer Plate
    • Channel Plate and Gasket
    • Driven Sprocket Support
    • Porosity
    • Misalignment
    • Loose or restricted
    • Fluid leak across the channels

Second Roller Clutch (452)

Damaged, not holding

1-2 Shift Solenoid Valve (305)

    • Stuck ON
    • Plugged

Forward Clutch

Low capacity shows up in Second Gear

Line Pressure

Low pressure (Refer to High or Low Line Pressure )

1-2 Accumulator (29-31)

    • Leak at the piston seal
    • Channel plate or case porosity

1-2 Accumulator Valve (323)

Stuck

2-3 Shift Valve (306)

Stuck in an upshifted position

PSA

Malfunction (Electrical or Hydraulic)