GM Service Manual Online
For 1990-2009 cars only

Vibration in Second, Third, Fourth, Fifth, or Sixth Gear for Chevrolet Avalanche - 2WD 2007

Checks

Causes

4-5-6 Clutch (with Output Carrier Shaft and Dampener) Hub Assembly (58)

Inspect hub assembly (475), dampener (476), and apply plate (477) for wear or damage.