[Lance Joseph]

I recently moved to Dade City and my 05 manual GTO w/51,000 miles has a bad rear end clunking sound. I already replaced all the mounts and bushings, and just swapped the rear axles to and the noise is still there, so I from reading posts it is probably the differential. I don't know if my Miami mechanic used wrong type of oil/slip as it seems from posts that could be the problem before I spend money on a used diff. The guy I have wants to replace the diff but he doesn't know GTOs, so I'm looking for someone who really knows these cars well and can take it apart, look at it and give me some straight advice. Thanks

 

[yellow]

Maybe check out gastiresoil.com under transmission and driveline. Lots of good info posted there by 2QWK4RU.

 

[Rich-Tripower]

The correct differential fluid is important. HOWEVER, these cars always have a drivetrain clunk of some sort, just nature of the beast as there is by design some amount of slop in the transmission, the differential and the half shafts. And when you add more poly bushings to the suspension and subframes the clunks become more prominent.