| Subject: | Grind, Growl or Transfer Case Disengagement |
| Models: | 2007-2008 Chevrolet Silverado |
| 2008 Chevrolet Avalanche, Suburban, Tahoe |
| Equipped With Magna Transfer Case RPO NQH |
This PI was superseded to correct SI document number. Please discard PIP4429.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may comment that the transfer case in the above listed vehicles grinds, growls or disengages. Vehicle will not pull under load. Other comments may be that the transfer case will disengage upon torque reversal i.e. shifting from reverse
to drive.
Recommendation/Instructions:
The above concern may be caused by the transfer case rear output shaft rear bearing retainer (snap) ring breaking. Reference item 27 in SI document 1824278. If the retaining ring is broken it can cause movement of the output shaft and possibly cause the
transfer case to disengage. Replace the retaining ring and rear output shaft. Also inspect the shift forks and all other transfer case components and repair or replace in the most cost effective way.
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.
