whining rear diff
Thread Starter
Heel & Toe
Joined: May 2014
Posts: 24
Likes: 2
From: Oklahoma City
whining rear diff
A couple of years ago, I had a local garage install a brand new rear diff with highway gears...but from the get go it whined, and has just gotten worse. When I questioned them, they said that it must have been installed incorrectly ( just off center a little ) and that once installed and driven, there is nothing that can be done about it...it that a fact ? Am I stuck with the whining unless I replace them ?
Racer
Joined: Jun 2013
Posts: 484
Likes: 43
From: NJ
Let me get this straight. They rebuilt it for you, then tell you it was installed incorrectly and don't want to do anything about it? 
How many miles did you put on it since it was installed? Is the whine when you slow down or is it all the time?
Its not the ideal thing to do, but most of the time it can be redone. You wont know until it is taken back apart and examined. As long as there is no damage to the gear set and they didn't totally **** everything up. Usually new bearings will need to be installed.
Shops like this scare the crap out of me.
How many miles did you put on it since it was installed? Is the whine when you slow down or is it all the time?
Its not the ideal thing to do, but most of the time it can be redone. You wont know until it is taken back apart and examined. As long as there is no damage to the gear set and they didn't totally **** everything up. Usually new bearings will need to be installed.
Shops like this scare the crap out of me.
Thread Starter
Heel & Toe
Joined: May 2014
Posts: 24
Likes: 2
From: Oklahoma City
thanks
No, I ordered it new , it wasn't rebuilt. I have put on a couple of thousand miles since then.
I was pretty surprised at what they said myself, as this is one of the best well known garages for classic cars/hot rods. They build their own drag cars, and seem to know what they are doing.
Thanks for the info....it whines when you accelerate/decelerate...do you think I can save it, or am I stuck ?
I was pretty surprised at what they said myself, as this is one of the best well known garages for classic cars/hot rods. They build their own drag cars, and seem to know what they are doing.
Thanks for the info....it whines when you accelerate/decelerate...do you think I can save it, or am I stuck ?
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
Well I'm guessing they won't fix it and it's on you. The first think I would do is check the oil level or replace the gear oil with something heavy duty. Then see if it quiets down. If not, your only choice is to pull it apart. the pinion shaft being loose is the only part I would play with if it was whining. The gears do wear into a pattern. Some say you can play with it, change it, reset the lash. I say that's mostly true but it's a gamble. (3,2,1, here comes the yelling) Do you spend $300 on new gears and another $300 to have them installed correctly or do you spend $300 to have the lash and contact area reset. If it was me, I would just have the rear reset with the old gears. The only time I woouldnt do it , is if the wear pattern was deep and more than obvious the gears really cut into each other.
With that said, are you sure it's not the pinion bushing making a humming sound? Gears really get a whirling noise. Almost like a jet engine on the highway.
With that said, are you sure it's not the pinion bushing making a humming sound? Gears really get a whirling noise. Almost like a jet engine on the highway.
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
From who?
It's been a couple years. What do you expect them to do?
I have put on a couple of thousand miles since then.
I was pretty surprised at what they said myself, as this is one of the best well known garages for classic cars/hot rods. They build their own drag cars, and seem to know what they are doing.
Thanks for the info....it whines when you accelerate/decelerate...do you think I can save it, or am I stuck ?
I was pretty surprised at what they said myself, as this is one of the best well known garages for classic cars/hot rods. They build their own drag cars, and seem to know what they are doing.
Thanks for the info....it whines when you accelerate/decelerate...do you think I can save it, or am I stuck ?
Drifting
Joined: Jul 2002
Posts: 1,995
Likes: 110
From: Garland Texas
I'm wondering the same thing. Where did they get a brand new diff?
Some gears are just noisy. I have had a few sets that somehow missed the honing operation at the factory. But the only way to be sure is to do a pattern check.
And, no, you can't install a vette diff a little off center. That excuse doesn't work.
Mike
Some gears are just noisy. I have had a few sets that somehow missed the honing operation at the factory. But the only way to be sure is to do a pattern check.
And, no, you can't install a vette diff a little off center. That excuse doesn't work.
Mike
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Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Change fluid to Amsoil Severe gear 75W-110. Thicker warm viscosity and synthetic will both help noise and reduce wear. For $30 it is worth a shot.
http://www.amsoil.com/shop/by-produc...?code=SVTQT-EA
"AMSOIL Severe Gear is compatible with most limited-slip differentials. If limited-slip differential chatter occurs, add AMSOIL Slip Lock® friction modifier additive."
EDIT: I have never had to use the additive with Amsoil.
http://www.amsoil.com/shop/by-produc...?code=SVTQT-EA
"AMSOIL Severe Gear is compatible with most limited-slip differentials. If limited-slip differential chatter occurs, add AMSOIL Slip Lock® friction modifier additive."
EDIT: I have never had to use the additive with Amsoil.
Last edited by 63mako; Jan 15, 2015 at 11:16 PM.
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
For those that do consider using the AMSOIL diff fluid (I use the 75w90 version of this in my 02 Z06 at the track), more than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested. 
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AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
C66 Racing #66 NASA ST2, SCCA T2
AMSOIL Dealer (Forum Vendor)
AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)