GM Service Manual Online
For 1990-2009 cars only

Noise in First, Second, Sixth, or Reverse Gear for GMC Truck Yukon - 2WD 2008

Checks

Causes

Center Support with 2-6 Low and Reverse Clutch Assembly (67)

Inspect for worn or damaged output carrier outer sun gear shaft front and rear bushings (458 and 460).

Output Carrier Assembly (68)

Inspect for a worn or damaged center support roller bearing assembly (485).