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2006 LBZ LLY Diesel Engine Vibration Felt At All RPM - keywords 6.6L align alignment balance balancer bolt crankshaft duramax harmonic idle LBZ LLY loose pin rate rough

Subject: 2006 LBZ LLY Diesel Engine Vibration Felt At All RPM

Models:2006-2007 Chevrolet Express, Kodiak, Silverado
2006-2007 GMC Savana, Sierra, TopKick
Equipped with the LBZ or LLY 6.6L Diesel Engine



This PI was superseded to update Model Years. Please discard PIP3647.


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

A dealer may encounter a customer concern of excessive engine vibration felt at all RPM.

The vibration discussed in this PI may occur with low mileage and may even be noticed during a PDI.

Recommendation/Instructions:

Complete the current SI diagnostics for any symptoms or DTCs found.

If an excessive engine vibration has been verified, inspect for a loose harmonic balancer bolt. If a loose balancer bolt has been found, the crankshaft harmonic balancer alignment pin/keyway will also have to be inspected.

If the crankshaft - harmonic balancer alignment pin is damaged, replace the alignment pin, and any other damaged components.

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.