71-Camaro-98

iTrader: (17)

Recently I have been hearing this slight moaning sound coming from the rear end of the car, mainly when I make a turn. It almost sounds like i've got something rubbing back there but I have no idea what. It varies in how loud it is sometimes but it went away for awhile. I raced a Porsche today and then it was back... I dk what it could be. Maybe the old 10 bolt is finally going out??

Blackhawk777

Possibly. I had that same issue before mine went a while back. It's most likely the carrier bearing starting to fail, or the gears in the diff are going out. I'd pull the cover off and see if you got any metal chunks in the housing floating around.

71-Camaro-98

iTrader: (17)

Anybody else?

9000th01ss

iTrader: (10)

A '98 should have an Auburn. It needs a good non synthetic gear oil with genuine GM or Ford friction modifier.

71-Camaro-98

iTrader: (17)

Why not a synthetic? And I dont know a whole lot about diffs. so if you could expand I would appreciate it.

9000th01ss

iTrader: (10)

Auburn diffs have cones on the side gears instead of clutches. Cones are metal to metal contact. There are powdered metal inserts in the carrier that the cones sit in. Synthetic lubes it too good I guess.
You should just read it on their website.

I know this because my first Auburn made a noise. I had regular gear oil in it with 16 ounces of cheap limited slip additive out of a tube.
I called their tech line and they said thats the most common problem they have--people using the cheap ****.
I did what they said I used GM gear oil and 4 oz GM or Ford additive (ironically GM was out so I used GM oil and ford additive). Only 4 ounces of friction modifier additive, GM gear oil and in a few miles it never made a noise again.

71-Camaro-98

iTrader: (17)

OK, so the sounds just got worse all of a sudden... I have made two videos of the sound, one from the inside and one from the outside. Just listen and you can here it, it sounds like a rub/moaning sound. It only makes the sound when I turn, never when I am going straight but it definitely sounds like its coming from the rear... I need some info on what it is... Thanks for the help.

9000th01ss

iTrader: (10)

That sounds like a bad bearing, hard to tell with video.
My car recently started with a noise so I took the rear apart to check the bearings, it was a bad axle and bearing but it didn't sound like that.

I did have a car sound similiar to the interior clip you have, this car had an Auburn and the wrong friction modifier.
What you can also do is jack one rear wheel up, take the trans out of gear and brake off. Try to turn the one wheel. You should be able to turn it not easy but with some resistance. If it's bad you'll hear the noise then too.

Whens the last time the rear oil was changed?

I just listened to it again and it sounds like posi clutch chatter, sounds like a steady whining sound. Change the fluid and friction modifier, use GM or ford friction modifier. It should go away in 20 miles or so. Still wouldn't hurt to pull it apart.

71-Camaro-98

iTrader: (17)

I just changed it twice in the last 6 months.. The second time was to fix a leak I had about 3 months ago. I ran synthetic in it before that and never had any problems. Then all of a sudden it started up...

71-Camaro-98

iTrader: (17)

I dont know that much about differentials... Is that a difficult thing to do? And how much would the part cost?

9000th01ss

iTrader: (10)

There are no parts unless you find something bad.
You cannot run synthetic in an Auburn and you cannot run with any other type friction modifier other than GM or ford.
You can, but it's going to make noise with it.
GM non synthetic gear oil and 4 oz GM friction modifier will get rid of any differential related noises unless there is a problem.
From what I hear thats clutch noise. Next time you make a sound clip get some speed, shut the engine off and coast. It's real hard to diagnose a noise over the internet.

But from what I hear it's making a noise similiar to what a few of my Auburns made. Auburns tech line says thats the most popular call they get, they said several a day. Since using their recommendations I never had a noise out of one again.