| Subject: | Clunk Noise When Shifting Into or Out of 4WD LO or Neutral |
| Models: | 2003-2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe |
| 2002-2007 Chevrolet Trailblazer |
| 2003-2007 GMC Sierra, Sierra Denali, Yukon, Yukon XL |
This PI is being updated to clarify the concern. Please discard PIP3408A.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Clunk or grind noise when shifted into or out of 4LO or neutral more noticeable with the engine running.
Recommendation/Instructions:
This is a normal operating characteristic by design due to low range being a non-synchronized gear.
To reduce the clunk condition, turn the engine off and then shift to 4LO.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
