Vibration or Transmission Output Shaft Damage/Oil Seal Leak (Repair Damaged Components and Install Revised Output Shaft Yoke Nut)

Some customers may comment on a driveline vibration or transmission fluid leaking onto the ground. The vibration is most noticeable at highway speeds or upon acceleration. This condition may manifest itself as a vibration that may be accompanied by a transmission output shaft oil seal leak. In extreme cases, this vibration may result in output shaft damage or engine block cracking.

A loose yoke nut may cause insufficient clamp load on the joint, accompanied by a vibration from an unbalanced driveline component (for example a bent or out of balance drive shaft or other worn component).

Repair any damaged components as required. To improve yoke retention, replace the output shaft yoke nut with P/N 12478169 and tighten the nut to 508-542 N·m(375-400 lb ft). Refer to Rear Oil Seal Replacement procedure in the Manual Transmission sub-section of the Service Manual.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: