No 3-4 Shift, Slips or Rough 3-4 Shift

WARNING: This page is about a different car, the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

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

Checks	Causes
Oil Pump Assembly (4)	Pump cover retainer and ball assembly omitted or damaged Faces not flat
Valve Body Assembly (60)	Valves stuck 2-3 Shift valve train Accumulator valve 1-2 Shift valve train 3-2 Shift solenoid valve assembly Spacer plate or gaskets incorrect, mispositioned or damaged
2-4 Servo Assembly (13-28)	Incorrect band apply pin Missing or damaged servo seals Porosity in piston, cover or case Damaged piston seal grooves Plugged or missing orifice cup plug
Case (103)	3rd Accumulator retainer and ball assembly leaking Porosity in 3-4 accumulator piston or bore 3-4 Accumulator piston seal or seal grooves damaged Plugged or missing orifice cup plug 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