Question about rear ends

[sneitzel]

A guy I work with has a 2002 TA WS6 6 speed, 120K

He has been having trouble with the rear end making noise for some time and things have finally gotten bad.

In the past, he had a shop here in San Antonio work on the rear end and install new gears but the result was a very noisy setup. The shop tried multiple times to adjust things but eventually gave up and reinstalled his stock gears.

He is currently looking for a replacement rear end but there is some confusion.

Can someone tell me what actually came installed from the factory? Gear Ratio? Limited Slip? What should he be asking for when calling junkyards?

Another alternative would be a good TRUSTED shop locally that could actually rebuild his stock rear end. It needs to be a place with experience. Quiet operation is by far the most important thing to him second to price then performance. Can any of the local (San Antonio) guys recommend anyone?

Other suggestions?

[Performin Norman]

In the future, if he has noise he should change out fluids. Some times fresh limited slip oil will fix the clutch noises.

However, since he thinks it is beyond that now, the 6M cars came with a limited slip housing 3.42 gears. If he goes with aftermarket gears, I strongly recommend he go with Motive gears. They work well in Fbodies and are very quiet and strong.

Also, I would not recommend used gears. I would install fresh ones.

[Jeff_in_Atl]

In the future, if he has noise he should change out fluids. Some times fresh limited slip oil will fix the clutch noises.

However, since he thinks it is beyond that now, the 6M cars came with a limited slip housing 3.42 gears. If he goes with aftermarket gears, I strongly recommend he go with Motive gears. They work well in Fbodies and are very quiet and strong.

Also, I would not recommend used gears. I would install fresh ones.

Very close except the 98-02 non SS and non Firehawk cars use a Torsen rear end differential. They do not have clutch packs like the 93-97 and the SS and Firehawk. (The SS and Firehawk used the Auborn differential.) Some Torsens are noisy. Mine was. I thought it was an axle bearing so I replaced it. It was still noisy but it never got any louder over time. The axle shafts seamed to have a bit play in them due to the diameter being a little smaller than I think they should have been. They do not need the limited slip fluid however GM issued a tech bulletin to add the fluid if owners complained about the noise. This is about the only time I would recommend using additives to quiet it down.

One thing I have heard of is play in the C clips allow the axle to slide in and out of the tube a little bit. I have heard of it sliding far enough to hit the brake caliper and make a rubbing noise. A Dremal will take off enough pretty quickly to fix this.

[Performin Norman]

Very close except the 98-02 non SS and non Firehawk cars use a Torsen rear end differential. They do not have clutch packs like the 93-97 and the SS and Firehawk. (The SS and Firehawk used the Auborn differential.) Some Torsens are noisy. Mine was. I thought it was an axle bearing so I replaced it. It was still noisy but it never got any louder over time. The axle shafts seamed to have a bit play in them due to the diameter being a little smaller than I think they should have been. They do not need the limited slip fluid however GM issued a tech bulletin to add the fluid if owners complained about the noise. This is about the only time I would recommend using additives to quiet it down.

One thing I have heard of is play in the C clips allow the axle to slide in and out of the tube a little bit. I have heard of it sliding far enough to hit the brake caliper and make a rubbing noise. A Dremal will take off enough pretty quickly to fix this.

You just clarified why the rear diff I bought off the net for my S10 was a clutchless design. It must have come from a 98 - 02 car.

[sneitzel]

Jeff,

That may be the source of the confusion.

The clutchless Torsen design is still a limited slip/posi-trac (whatever you want to call it) type differential correct? ie. power going to both wheels and transferring power when one wheels slips

He has found a few but the places told him they weren't sure of the ones they had were LS or not.

[Jeff_in_Atl]

Jeff,

That may be the source of the confusion.

The clutchless Torsen design is still a limited slip/posi-trac (whatever you want to call it) type differential correct? ie. power going to both wheels and transferring power when one wheels slips

He has found a few but the places told him they weren't sure of the ones they had were LS or not.

You can go hear and read all about them.
http://www.torsen.com/
The Torsen is a really good design. It uses a worm gear between the gears on the ends of the axle rather than spider gears and clutches. GM called it a limited slip. The worm gears do limited the amount of differential speed between the 2 shafts. They will easily spin both tires. However if 1 tire is getting no traction at all it will not send the power to the other wheel like a differential with clutches. It will spin the one tire without traction just like an open differential. As you can see on their web site they are now doing the worm gears and clutch packs to overcome this inherent problem. However the original design does have one advantage over clutch type differentials. It will allow the 2 axles to turn at different rates freely when cornering and without the noise that the clutches make on a clutch type. The real advantage is during high speed corning which I had a personal encounter with on the original 95 clutch type axle in the Camaro at about 70 mph on the bridge from I85 north to I285 west in damp but not raining conditions. Thank you BFGoodrich for KDWs that will regrip after letting go. I will say this, I have looked to see if they make a Torsen for the Vette if that tells you anything. The Torsen is a much safer differential for street driving. It won't steer with the rear as much as clutch types.

BTW I don't think any V6s came with 3.42 gears so if you find a 98-02 housing with 3.42 gears it's either a Torsen or an Auborn out of a SS or firehawk.

Also 99% of mechanics will jack up a factory 98-02 (non SS or Firehawk) V8 car, spin 1 tire and see the other going the opposite direction and say the rear end is either not posi or the clutches are slap wore out. They are absolutely WRONG. The only way to really tell is to take the back cover off and look for the funny looking worm gears.

[Jeff_in_Atl]

Here check out this thread.
http://www.f-body.com/forum/showthread.php?t=11901

[Injuneer]

Alll the V8 cars, Camaro and Firebird, came with:

-a limited slip differential of one type or another. ("G80" on the build tag)

-They all have disc brakes.

-They all have ABS (3-channel, single sensor on top of diff housing).... but see next line.

-If his car has the optional traction control ("NW9", on the build tag - ASR) he has to find a rear axle assembly from a similarly equipped car, and it will have the 4-channel sensor system, with a sensor on each axle end plate, and a reluctor gear on each axle behind the hub.

-As previously noted, all the M6 cars (except the 93's) left the factory with a 3.42:1 rear axle ratio ("GU6" on the build tag).

Probably be a good idea to stick with a rear axle assembly from a 98-02, since they will have the LS1 rear brakes/e-brake setup.

[MN6WS6]

One other note on junkyard rearends. If you get one, you most assuredly want to pop the cover off and make sure there's no hard parts lying around or stuck to the magnet. I would HIGHLY recommend sliding the axles out and replacing the axle bearings and seals at this time.

Here's where it gets tricky. Technically, you cannot replace the pinion seal without tearing down the entire rearend. The old "count the threads and put the nut back on in the same place" is just not very accurate, but has worked for some people. After having two rearends blow up in two different vehicles within 250 miles of a pinion seal replacement with no other changes, I would say don't do it. If you do want to do it, you need to take a torque rating of the rotational force of the pinion nut with the axles out of the rearend. This can ONLY be done with a beam or dial-indicating torque wrench. Replace the seal and tighten the nut little by little, and each time you tighten it, check the rotational torque. Keep going until you get rotational force back to within a couple of inch pounds of it's prior reading. There are several websites that cover what I'm talking about if I've lost you.

When you get it back together, I would recommend full synthetic lubricant. These have the friction modifiers in them so you don't have to buy the additive from the dealer, not to mention it makes the bearings and gears last longer.

[Al 96 Ram Air T/A]

To add, if you're going for a rebuild, use a crush sleeve eliminator kit. I used one from Ratech, which replaces the crush sleeve with solid shims.

I then upgrade the bearing cap bolts to ARP studs, and got a quality diff. girdle with pre-load studs. I use full synthetic lube, either standard weight, or in the summer, 95(?)w- 145 (I think that's it). My pinion seal leaks a bit, but not enough for me to care. Most seals leak....just part of the fun. I look at it this way...it self-flushes so I add some every year