Differential rebuild inquiry

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Feb 12, 2012 | 06:27 PM

LawdoG247

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Instructor

Joined: Feb 2012

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From: Acworth Georgia

Differential rebuild inquiry

Hello all, I purchased a used 2001 z06 about a week ago with 56k miles. The differential has recently developed a hellacious whine once speeds surpass 50mph in any gear. It wasn't doing this during the first few days, much less at the dealership, conveniently.

I've been doing tons of research riffling through multiple posts regarding this issue on this board and various others. I've come to the conclusion that I'll need to have it rebuilt, as I changed the fluid (taking care to add the proper amount of friction modifier) and the noise persists.

So my question is, how much should I expect to pay to have it rebuilt with 3.90 gearing installed? I live in the metro Atlanta area if any locals want to chime in. I was really excited about owning one of these, but I must say this has really knocked the wind out of me!

The dealership (www.buyavette.net) provided a free 2 year/50k mile warranty that covers the engine and transmission only, so at least I have that safety net in the event more problems arise.

Last edited by LawdoG247; Feb 12, 2012 at 06:29 PM.

Feb 12, 2012 | 08:22 PM

craig04c5

Melting Slicks

Joined: Jan 2004

Posts: 3,012

Likes: 15

From: Jensen Beach FL

$1700 to $1900 and while you are at it add a 1/4" tunnel plate to stiffen up the body.

Feb 12, 2012 | 08:55 PM

Bob K

Melting Slicks

Joined: Nov 2002

Posts: 2,884

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From: Jamison Pa

St. Jude Donor '11-'25

Some Vendors to use

rkt56 or RPM are both vendors on the site and do outstanding work.

$1700-1900 would be about right if you pulled the rear and upgraded the l and R shafts with new Z06 parts. Check the pricing on either site.

Rick has done work for me in the past and was super to deal with. RPM also has a great rep here.

Bob K.

Feb 12, 2012 | 09:02 PM

LawdoG247

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From: Acworth Georgia

Although I am mechanically inclined, I lack the space/time/tools required to pull the rear myself. I work full time and attend college in the evenings all week, plus it's my daily driver. So I'm kindof forced to put it in the shop and get a rental if I want the repairs done in the next month or so. I've read a lot about people driving 40k plus miles with this issue without having any major damage occur. Hopefully I'll be able to ride it out until summer break where I could possibly tackle this job at a buddy's house. Thanks for the replies!

Feb 13, 2012 | 01:41 PM

Roc87

Burning Brakes

Joined: May 2002

Posts: 831

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From: Albuquerque NM

Just went through this. Had Rick at RKT56 build me a diff. Was originally going to have him rebuild the one out of the car, but my work schedule wouldn't allow that. So I paid the core fee (Rick will want to know if you have a single rib or a 3 rib diff if he's building you a core). Once core fees were paid and the diff rebuild fee was paid it was built in a few days and shipped out. I took my vette to a local shop along with the diff and 24 hours later I was breaking in the new gears and the old one was on its way back to Rick. 3.90's may be a bit much since you have a Z06 with the MM12 trans. Maybe others will chime in with their experience with the Z and 3.90's

Feb 13, 2012 | 01:45 PM

LawdoG247

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Joined: Feb 2012

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From: Acworth Georgia

Yea, I've since been looking at going with the 3.73's instead. Would you mind ballparking how much you spent an all that in total? Was it worth it? Has it cleared up the issue completely?

Feb 13, 2012 | 01:49 PM

Roc87

Burning Brakes

Joined: May 2002

Posts: 831

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From: Albuquerque NM

It has cleared up the issue

. The whine/grinding noise started very quietly and got louder. I'd say from the time it started til I had it fixed was 3k miles. Since it wasn't an overnight thing, it just seemed like the car got louder, but it is sooooo much nicer to drive now that the diff isn't chewing on itself. I had posted a thread about the diff noise (If you search my user name for posts, there is a reply with a video of another car with the same noise). It was absolutely worth it. I don't have a vette for MPGs but with the 3.90s and the 6 speed I only tach about 250rpm different than my fathers '98 with an auto and 2.73's. I'll send you a pm for costs.