GM Service Manual Online
For 1990-2009 cars only

No 2-3 Shift or 2-3 Shift slipping, Rough or Hunting

Checks

Causes

Oil Pump (4)

Stator shaft bushings scored or off location

Valve Body Assembly (60)

    • 2-3 Shift valve train stuck
    • Gaskets or spacer plate incorrect, mispositioned or damaged
    • 2-3 Accumulator valve stuck
    • Face not flat
    • Chips in servo feed oil, orifice #7 in spacer plate
    • Mislocated valve body to spacer plate checkball or checkballs

Input Housing Assembly (620-621, 646-655)

    • 3-4 clutch or forward clutch plates worn
    • Excessive clutch plate travel
    • Cut or damaged 3-4 clutch or forward clutch piston seals
    • Porosity in input clutch housing or piston
    • 3-4 clutch piston checkball stuck, damaged or not sealing
    • Restricted apply passages
    • Forward clutch piston retainer and ball assembly not seating
    • Sealing balls loose or missing
    • Input housing (621) cracked or broken

Case (103)

3rd accumulator retainer and ball assembly not seating

2-4 Servo Assembly (13-28)

2nd apply piston seals missing, cut or damaged