# 2004 gto rear end thump/vibrate/growling noise



## 5.7RedGto (Jun 29, 2011)

hey guys so i have had my 04 gto for a year now and had no problems until a few weeks ago when my diff was making a noise. I had a warranty so brought it to a trans shop and my warranty company provided the trans shop with a used whole rear end to swap in. (Wasn't to happy about that one) Anyway since i got it back every time i take a turn like into a parking spot or drive way a noise comes from my rear end. It usually happens at idle speed to about 5mph at the most. It sounds like something is vibrating and thumping and sometimes sounds like something is rolling around in my trunk and hitting the side of it. Some times it will vibrate and thump and sometimes it sounds like something is hitting in the trunk. It can do it a couple times in a row or not at all. Ive researched the problem and i saw the driveshaft may be bad or the LSD could be bad. I took it back to the trans shop and they said they think my tire could be rubbing or the rotor. I really doubt it is due to this noise. Does anyone have any ideas or suggestions because this noise is driving me crazy. Thanks everyone


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## svede1212 (Nov 1, 2005)

Drain the diff, put in Torco 90w140 and 2 oz of *F-type* friction modifier. They probably didn't put in the right stuff.


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## 5.7RedGto (Jun 29, 2011)

should i get synthetic or regular gear oil?


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## GTO JUDGE (May 14, 2005)

5.7RedGto said:


> should i get synthetic or regular gear oil?


Synthetic. Surely that used rear end had a warranty? It should have. Call the trans place. Be animate you want them to service it, DO NOT allow them to sweet talk you or intimidate you.

Used rear end? What is the history of that used rear end? Was it one that had issues and was replaced by GM through GM warranty? Was it rebuilt? Was it serviced? 

My bet is they don't have a clue on this rear end. MOST do not. Ask them if they know the history on these rear ends from the whine to the clunking noises to the proper amount of friction modifier and the CORRECT kind of friction modifier. Sounds to me you traded one problem for another.


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## svede1212 (Nov 1, 2005)

Dana Australia that made the rear end recommended regular and not synthetic fluid and Torco seems to work the best.


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## 5.7RedGto (Jun 29, 2011)

The rear end they installed does have a warranty and every time i call i tel them their work is NOT satisfactory and that they were recommended to me by a family mechanic which will no longer be the case if this isn't fixed. I had them get me new diff fluid and torch friction modifier and so far it seems to be fine. They originally told me though they were going to rebuild my diff which i was fine with and if not can't and need a new one, it would in fact be remanufactured. i called in the morning and they told me they were getting me a remanufactured rear which was basically new. Then after i got my car back and heard the noise i jacked up the rear and took off the diff cover and took a look at everything which led to me to call them yelling which in return got the truth out of them that it was a used rearend the warranty company provided. We came to a agreement that if causes me problems i will in fact get a new rearend which is a signed agreement. Some shops have some nerve!




GTO JUDGE said:


> Synthetic. Surely that used rear end had a warranty? It should have. Call the trans place. Be animate you want them to service it, DO NOT allow them to sweet talk you or intimidate you.
> 
> Used rear end? What is the history of that used rear end? Was it one that had issues and was replaced by GM through GM warranty? Was it rebuilt? Was it serviced?
> 
> My bet is they don't have a clue on this rear end. MOST do not. Ask them if they know the history on these rear ends from the whine to the clunking noises to the proper amount of friction modifier and the CORRECT kind of friction modifier. Sounds to me you traded one problem for another.


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