The Torsen is a torque sensing rear, not a locker. I gave my description of a GM locker as it was called.

The torsen is a decent piece & should live with moderate power. You should still use the additive to prevent the potential noise as stated above. It is probably the best alternative for the 7.5" rear.

The repeated misconception here is that a lack of additive hurts the "gears".... this keeps getting repeated incorrectly. The gears are adequately lubed with the standard gear oil. The chatter is due to the posi locking up too tightly (due to the oil not being slippery enough) The additive actually makes the posi clutches release smoothly to prevent chatter.

This is not internet heresay, I routinely rebuild, modify & set-up rear ends as part of my automotive business.

 

I have 2 Camaros, both with Zexel Torsen differentials. One is an 88 Camaro SC which I installed a SLP take off posi (Zexel Torsen) into it. The other is a 98 which 98's with M6 3.42 ratio got the Zexel Torsen.

If your rear is a 2.73 gearset, that torsen in your pic will fit. The 3 series carrier has a separate ABS reluctor ring on it meaning its a thicker carrier, that carries smaller gears.

This posi is a strange posi to say the least. When jacked up, the wheels will rotate in the opposite direction like an open diff. Some chatter, mine don't. Only know it'll make a lot of noise during turning if you suffer from it. GM friction modifier will clear up the chatter. I don't use friction modifier, I don't run synthetic in the rear on my 88. Quiet rear.

I can get it to 1 wheel peel if I turn at the same time as burning out. It's not the traditional 1 wheel peel, the tire with traction WILL get you going almost as well as a standard 2 wheel pull. This happens because as long as there is friction against the "free spinning" tire, power will be passed to the tire with friction. It's not as good as both tires hooking, but it is significantly better than 1 wheel peel.

This has a small glitch though. The tire that is free spinning must have some frictional resistance against it in order to pass power to the other wheel. Problem. If 1 tire is in the air, no tires recieve power. Applying the brakes during this time will give necessary resistance to move.

First hand, it sucks. I was driving in lite snow in my 88, my drivers side went over a pot hole, not deep, half the length of the car. For an instant, no power was being applied to my wheels, then SLAM, power back, jerked car, lost control, did a mini drift across 4 lanes for a good 1/2 mile trying to recover.

Get the SLP Heavy Duty Torsen, it has clutches in it to prevent that occurance.

 

Thanks for replying. Lots of good stuff here! I'm running the standard (for A4) 2.73 gearing. Since your message, I removed the cover from my 01. The differential is a twin sister to the one in the picture.Thanks for identifying the unit for me. I'm staying with the 2.73 gears Mike. I see Richmond makes thicker ring gears for the 2 series carrier (ie Summit RMG-4900071). I was going to change them out but after coming across an 11 second club A4 owner using the 2.73 and getting 1.6 second 60' launches, I've come to believe the claims of the LT1's low rpm torque advantage. Wish I could point to the forum and specific msg where the claim was made but can't find it now. I realize what I'm writing is pretty unbelievable but I backread his posts and followed his links to the drag strip. Perhaps this hero frequents this board as well - sure hope so.More useful info Mike....Owner's manual for my 01 says to use 4 oz. of the additive, also specifies full synthetic for the Thorsen. I was going to use a valvoline blend but will go back for a full synthetic. I'll go looking for the RedLine lube now. Thanks...
I'm thinking the gear lube change was the car's first ever or at best the first in 95k miles. A lot of details but short story on the car was one owner, lady driver. Significant repairs like steering, suspension, water pump and opti. Zero aftermarket modifications. Car was filthy but still looked maintained. In other words, it was a daily driver by someone who just wanted a sporty look. It was a great deal.

As for power to this setup; I'm where I want to be with it now. Just a catback, cai and a handful of cheap tricks. Even with 100k it feels like I'm riding a slingshot. All my CD cases come shooting back on me when I make a spirited escape. Besides, my mad money is earmarked for that M6 LS1 with LS6 aspirations.

Thanks

 

I could tell you had hands on experience Lonnie. Your advice is well taken and seriously appreciated.
Thanks

 

This is all good information for me to file. I'll now know what is happening with my Thorsen on the 01 rather than wonder if there isn't something going wrong with it. What a great bunch of people here. I really appreciate the input from EVERYONE! This forum is more than just about the cars....

blessings

 

I just wanted to comment on the "lack of F.M. damaging gears/bearings" statement. I know this is false. My 94 Z28 w/30k has the stock Auburn and has allways been maintained. The car has been autocrossed for the last 7-8 years, so the diff fluid was flushed annually. The Auburn finnally started slipping on me at the end of this years season. I drained the fluid and replaced it with Redline 75/80 "NS" fluid. This is full synthetic gear oil with no f.m. ,(hense the ns, "non slip") The old Auburn is working well again and I am told it should last me another season or two. However, this thing is very noisy now. I get alot of clanking and clicking mostly at slow speeds,(like driving through a parking lot) But like a fellow autocrosser/road racer told me, noise is good! That means it's working. It could be the soft compound tires making it sound worse than it is, because it's not as bad on street tires. Anyway, I am now shopping for a stock Auburn to replace this one as it's only a matter of time until even the "ns" fluid won't hold it. But I'm not in danger of damaging anything in the mean time. This is a very common practice among autocrossers/road racers.

 

My factory 10 bolt, 7.5" Auburn posi (1997 Z28 bracket car) is not holding off the line. Only the right rear turns during the burn-out and launch off the line. So, I've ordered a replacement High Performance Series Aubrn "cone-clutch" posi. Is that the the best option? And what performance should I expect (lock-up and years of service)?

 

The Auburn High Performance series diff is exactly the same as the o.e. unit. So it's not any better than what you had. However, it does qualify for the DREX program. (Auburn's differential rebuild exchange program). Which means if it wears out within the next 4 years, for $100 you can send it back to Auburn for a fresh rebuilt replacement. More information about this is on their website, but that's the gist of it.
If you were looking for a better than o.e. diff, then the Auburn Pro series is much stronger than the one our cars came with.
And if you must have the absolute best diff available for our cars, then the Zexel T2R is what you want. But it may be overkill for bracket racing.

 

I ended-up with the Auburn Pro-Series posi after all. I do most of my own work, however, in this instance the local differential shop made me a "real deal" on the Pro unit installed. Basically, just a few dollars more than I would have paid for the Auburn posi alone. So, I'll be ready to go again for the first bracket race this weekend. I'll let you know how well it holds during the burn-out and launch.

 

I'm curious. What type and brand of gear lube did the shop put in for the Auburn and did they add the limited slip addititive. By any chance do you know how much they used, if any?

thanks

 

The Auburn unit comes with its own additive. Also, I provided Royal Purple 75-90 synthetic which contains the Limited-Slip additive as well. So, I’m not sure if the Auburn additive was used. The additive only eliminates the ratcheting (clicking) noise during no-load turns. I have my first bracket race this weekend, hope the new Auburn holds well off the line and lasts a long time.

 

The Auburn isn't supposed to use synthetic. This is why I asked the question.

Look here: http://www.auburngear.com/aftermarket/faq/#q2

Also, I was surprised that the owner's manual for my 95 says to only use 4 ounces of the additive. Things may have changed but just to give you a heads up on this.

GM switched to the Torsens when they began using the LSx engines. The Auburn is a good differential but it was showing its limits as the torque began to increase with the later engines. I swapped out my Auburn for a Torsen from a 2000. It was beginning to one wheel peel and there was some disintegration going on after 95k miles.