# 04 Rear Diff Replace



## amdoverclocker (Dec 21, 2010)

04 with a whinny and out of spec diff. The rear tires will move a significant amount(~1"+) between the gears before moving the drive shaft. It's probably time for a rebuild or replace. For the life of me I can't find some where to buy a rebuilt diff. Any pointers? I don't need anything special as this will always be a sub 400HP car. Thanks! :cheers


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## amdoverclocker (Dec 21, 2010)

Really? Nothing?


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## dms (Jun 27, 2005)

GM did not support overhauling this diff. If there was any issue, they just replaced it.

mike
dms


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## amdoverclocker (Dec 21, 2010)

Thanks Mike. Know of anywhere that sells them?


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## Rukee (Feb 8, 2007)

Do a search for `04 diff replacement, there are several threads that cover how to install the stronger `05-`06 diffs into an `04.


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## jpalamar (Jul 22, 2008)

Have you tried fresh fluid and FM yet?


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## GTO JUDGE (May 14, 2005)

dms is correct on this. The rear diff was a single part number. It's a Dana part. GM removed the entire rear under warranty and sent it back to Dana. GM made money on this. There is big money to be made in back charges to vendors. 

GM dealers did not open up the rear end. They were instructed to first drain the old oil and replace with fresh with friction modifier. They did this to see if it corrected the issue. It didn't if the whine was too extreme. The next step was ordering a new rear and installing it. 

These cars are now in the way out of warranty stage. My opinion? Find a place to rebuild yours and get a warranty with it. You won't know what issues you may encounter purchasing one rebuilt. There is an art to building rear ends. You don't want to purchase one blindly then find you have this issue all over again or worse.


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## svede1212 (Nov 1, 2005)

gForce engineering does rebuilds and stocks all of the parts


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## amdoverclocker (Dec 21, 2010)

Yeah I knew GM just replaced the entire thing but I was hoping to just find a rebuilt one already. Oh well. There are plenty of speed shops around me so I'll have to start calling them. 

jpalamar - Yep. Done that twice now. I want to do it again here soon and use Torco this time.

Thanks all. I'll update this thread when I find a fix for my problem.


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## motoristx (Apr 27, 2010)

i know its very expensive, but, i'm going to be doing this in the summer of 2012 - GTO BOLT IN 9" IRS


its the Geforce custom built 9" IRS, it comes with everything you need, Axles, drive shaft, stubs, and i think your choice of gears. Again, Its very expensive.

other then that, They have given me a few alternatives... but, i drive my car like i stole it, and i want it to be able to handle the abuse


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