2007 Mustang GT. Last spring I had 4.10's installed. Just had a Dynatech 3.5 Aluminum Drive Shaft Installed (this week). There is a loud annoying whine/grind sound whenever I let off the pedal. The Mechanic is a pro, races Mustangs. He said the Mustang has a noise problem anyway in the rear, if I can live with the noise no problem Or he could pull the rear end, check the wear pattern on the gears and possibly re-shim. Does this sound ok?

 

ummm, in my opinion, you are burning out the gear. I'm not a mechanic, but they should be quiet. I had 3.73s in my 01 and they didn't make a sound. Noise from the gears is not good. I'd take it to somebody who is going to stand behind his work because this guy is trying to get out of fixing it, and he'll try to charge you for fixing his f**k up. If it was done right in the first place you wouldn't have to bring it back.

ps put your lawyer on retainer, have a competent mechanic fix it (make sure he know the score before he touches your car) and send him the bill. He'll say "sue me" and the competent mechanic will testify against him. Good luck and there will be alot of agrivation.

 

I have to agree....I think you need a new mechanic. It sounds like a pinion bearing noise. Check to see if the diff is full of lube first, then, find someone that knows rear-ends.

 

Whine and grind are two totally different noises. With that said a grinding noise needs to be fixed. Whatever it is, it's probably too late to fix.

As for a whine. Sure quieter is better but a little whine does not define a bad rear end.
I've taken some high mileage stuff apart that had a whine and found nothing wrong. It's usually just not an ideal tooth contact and if it's not way out it can easily go on to a life life.

 

It's a whine, especially when I decelerate. Started a few weeks ago. Had a Dynatech 3.5 aluminum drive shaft installed this week. Sound is more annoying. The guys that installed my new suspension and drive shaft did fine work...for $900.00...I have another mechanic (builds race cars) at $85.00 an hour (ouch). I'll talk to him. Thanks guys.

 

So...would it be recommended to have the rear end checked out? The mechanic's that did the suspension said pretty much the same thing. Suggested checking the wear patterns and resetting the shims. Sound correct to you?