Harsh, Soft, Delayed or Slipping 4-5-6 Shift

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Checks	Causes
4-5-6 (with Turbine Shaft) Clutch Assembly (56)	Inspect for damaged or worn clutch plates (433-435). Inspect for damaged piston (439), piston dam (437), dam retaining ring (436), and clutch spring (438). Inspect for improper selective 4-5-6 clutch backing plate retaining ring (431). Inspect for cut, worn, or damaged turbine shaft fluid seal rings (442).