I had mine replaced under warranty they replaced my diff with p/n 92174633, but I believe there's a new p/n 92187413. The work order states "Cause: found worn differential gears causing whining noise. Replaced differential assembly and topped with fluid. F2143 Carrier assembly (complete) rear differential replace 439 WP 2.2. Here's some additional info from ls1gto.com:
http://www.ls2gto.com/forums/showthread.php?t=117377
http://ls1gto.com/forums/showthread....hlight=whining
Also found this TSB on ls1gto.com:
TSB.....#PIP3387D Dana Rear Differential Carrier Parts Availability - keywords broken chatter growl leak noise shudder vibration whine - (Apr 3, 2007)
Document ID# 1951598
2005 Pontiac GTO
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Subject: Dana Rear Differential Carrier Parts Availability - keywords broken chatter growl leak noise shudder vibration whine #PIP3387D - (04/03/2007)
Models: 2004-2006 Pontiac GTO
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This PI is being superseded to update Condition/Concern and subject line. Please discard PIP3387C.
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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Any concern with the rear differential carrier in the 2004-2006 Pontiac GTO that would require parts or sealer replacement other than a fluid change, axle seal or pinion seal.
Recommendation/Instructions:
This differential carrier is not serviceable at the dealer. Currently, the assembly will need to be ordered through GMSPO. A SPAC case may be necessary if the assembly is on back order.
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.