Think I got burned?

**supercharged666** · 10-27-2014, 12:41 PM

I just recently purchased a 99 T/A a couple months ago and I herd a noise coming from the rear end which at the time I thought was worn tires cause they were super bald but now I am pretty sure is a right rear axle bearing. I was able to put the car on a lift and put it in drive and run it to listen for the noise and sure enough it is coming from the right rear tire. It is a howling growling type of noise. So ok I get that I have to replace the bearing but what is more desturbing is that I think the car has a v6 diff in it. When I spin the tires in neutral they both turn opposite ways not like a possi where they turn the same way and the car also has a steel driveshaft not an alumin one. Can anyone shed some light on this. Is this a diff from a v6 car?

**pajeff02** · 10-27-2014, 05:22 PM

The wheel bearing rides on the axle in the stock rear -- not unheard of for them to go bad, especially on a 15 year old car. These rears have a Torsen style posi that is different than a clutch type posi. Easiest test is to lay down some rubber and count the stripes on the pavement.

**theorangeguy** · 10-27-2014, 05:44 PM

Originally Posted by pajeff02

The wheel bearing rides on the axle in the stock rear -- not unheard of for them to go bad, especially on a 15 year old car. These rears have a Torsen style posi that is different than a clutch type posi. Easiest test is to lay down some rubber and count the stripes on the pavement.

Haha that just might be the best advice I've ever seen in this forum Jeff!

**pajeff02** · 10-28-2014, 02:21 AM

I am almost certain that when I bought our car the rear wheels did exactly the same thing when I had the car on the lift. Only one sure way to find out though without popping the rear cover.

**RONS98TA** · 10-28-2014, 03:20 AM

Would you like 1 stripe or 2 with your burnout sir? LOL By all means 2 of course.

**supercharged666** · 10-28-2014, 06:21 AM

On my 98 TA the wheels would both turn in the same direction when on the lift in neutral. Also what about the driveshaft. In my 98 it was an Alumin one, my 99 is steel? I thought all ls1 came with alumin?

**scott5** · 10-28-2014, 08:06 AM

Your car auto or 6 speed

**supercharged666** · 10-28-2014, 08:32 AM

Both my cars were auto

**supercharged666** · 10-28-2014, 09:03 AM

It's just weird that both rear ends are so different? When both cars are the same except for the year.

**pajeff02** · 10-28-2014, 12:07 PM

As long as it is a posi rear, internally they are the same except for maybe the ratio.

**supercharged666** · 10-28-2014, 01:34 PM

Well I will have the rear cover off soon to do the bearing so we will see what we got inside.

**Cutlass** · 11-02-2014, 03:51 AM

If I remember correctly 98s had auburn clutch posi. 99-02 had the Torsen posi. Torsen posi will act funny on a lift.
Another thing to remember is 98s are a real odd ball year. There are tons of differences between 98s and 99-02.
I think your 99 should have and aluminum Dshaft, so you could be on to something there

**35th-ANV-SS** · 11-02-2014, 05:43 AM

The car is 15 years old now so it's possible someone changed drive shafts at some point. What brand is the drive shaft?

**cammed goat** · 11-02-2014, 08:28 AM

I'm with Jon on this. Maybe the previous owner twisted the factory shaft while racing and had a steel one fabbed up? And I thought all 4th gens had V6 diffs. That's why they failed so easily.

**67CamaroRSSS** · 03-17-2015, 10:57 AM

I know this is a late entry but 2.73 geared cars came with a steel drive shaft. This is what was on entry level Z28's, Formula's and TA's.

Optional 3.23 gears (standard on SS and WS6) had an aluminum drive shaft.

This only applies to A4 cars as all M6 cars had an aluminum drive shaft.

**Firebirdjones** · 03-18-2015, 04:34 AM

I believe Cutlass is correct on the torsen, and Jim is correct on the driveshaft.

98's were still using the cone style Auburn posi units which act like everyone describes, both wheels turn the same direction when suspended in the air. 99 switched to Torsen diffs which act like lockers (but they are a screw type mechanism) the wheels will not spin the same direction when suspended in the air. One tire has to slip on the pavement before the torsen locks the other tire.

On driveshafts Jim is correct as far as I know, When it comes to automatics, steel driveshafts came in the auto's with 2.73 gears. You only got the aluminum driveshaft when the car was ordered with optional 3.23's, or when you ordered an SS or WS6 with an auto because the 3.23's were standard equipment in those cars.
All the 6 speeds regardless of model came with 3.42's and aluminum driveshafts. You could always check the RPO codes on the automatic to see what rear gear the car came equipped with, that would lay the driveshaft dilema to rest.

So I don't believe the original poster has anything unusual going on to be suspicious about. You just had an axle bearing go bad and that's not all that uncommon.

**theorangeguy** · 03-18-2015, 05:28 AM

Originally Posted by cammed goat

I'm with Jon on this. Maybe the previous owner twisted the factory shaft while racing and had a steel one fabbed up? And I thought all 4th gens had V6 diffs. That's why they failed so easily.

I'm not sure on that one...the Y87 v6 Fbody's had a posi and the standard ones didn't...with that said, it could still be a 10 bolt but just a cheaper version of it that only spins one wheel instead of 2.

**Firebirdjones** · 03-18-2015, 05:32 AM

Well if you guys want to look at it that way, then technically we could just call these 7.5's 4 cyl rearends, because it's the same thing they used in the Vega's and Monza's in the 70's

**INMY01TA** · 03-29-2015, 07:55 AM

You don't want the aluminum driveshaft, trust me.

**Firebirdjones** · 03-29-2015, 08:37 AM

Yup, and a cheap alternative that I like to do is to run the steel driveshaft. The aluminum piece was one of the first things to come out of my wifes car.