GM Service Manual Online
For 1990-2009 cars only

No 3-4 Shift/Slipping or Rough 3-4 Shift

Checks

Causes

Oil Pump Assembly (4)

    â€¢ Pump cover retainer and ball assembly omitted or damaged
    â€¢ Faces not flat

Valve Body Assembly (60)

    â€¢ Valves stuck
       - 2-3 Shift valve train
       - Accumulator valve
       - 1-2 Shift valve train
       - 3-2 Shift solenoid valve assembly
    â€¢ Spacer plate or gaskets incorrect, mispositioned or damaged

2-4 Servo Assembly (13-28)

    â€¢ Incorrect band apply pin
    â€¢ Missing or damaged servo seals
    â€¢ Porosity in piston, cover or case
    â€¢ Damaged piston seal grooves
    â€¢ Plugged or missing orifice cup plug

Case (103)

    â€¢ 3rd Accumulator retainer and ball assembly leaking
    â€¢ Porosity in 3-4 accumulator piston or bore
    â€¢ 3-4 Accumulator piston seal or seal grooves damaged
    â€¢ Plugged or missing orifice cup plug
    â€¢ Restricted oil passage

Input Housing Assembly (621)

Refer to No 2-3 Shift or 2-3 Shift Slips, Rough or Hunting .

2-4 Band Assembly (602)

Worn or misassembled