GM Service Manual Online
For 1990-2009 cars only

No Third Gear, Slips in Third Gear

Checks

Causes

Direct Clutch

No apply or slipping

Piston and Seal Assembly (518)

Binding, cracked, or leaking

Clutch Plates

Worn friction or broken splines

Snap Ring (520)

Out of position

Springs (519)

Binding

Direct & Coasting Housing and Input Shaft (520)

    • Damaged or cracked
    • Restricted feed holes

Housing Retaining and Ball Assembly

Missing or loose

Direct Clutch Fluid Routing

Fluid leak or restriction

    • Valve Body
    • Gaskets & Spacer Plate
    • Channel Plate & Gasket
    • Driven Sprocket Support
    • Porosity
    • Misalignment
    • Looseness
    • Fluid Restriction
    • Fluid leak across the channels

Driven Sprocket support Seals

Leaking

Input Shaft

    • Leaking seals
    • Damaged or misaligned sleeve

2-3 Shift Solenoid Valve (305)

    • Stuck OFF
    • Leaking

2-3 Accumulator

    • A leak at a piston seal
    • Channel plate or case porosity

2-3 Accumulator Valve (330)

Stuck

Line Pressure

Low pressure (Refer to High or Low Line Pressure )

3-4 Shift Valve (319)

Stuck in upshifted position

PSA (13)

Malfunction (Electrical or Hydraulic)