Torsen or Posi

**GatorSS** · 01-01-2007, 08:00 PM

Torsen here.

**01Z28M6** · 01-02-2007, 03:57 AM

Originally Posted by 9t8z28

Torsen or Posi differential---------What rear do you prefer? What problems have you heard about them? Which one do ya think is better?

I had a Torsen in the 97SS and I have a Posi in the 98z. I have a set of 4:10s I am going to put in the 98. Which rear should I use?

I'm trying to understand what you are asking. It's an interesting thread.

The Torsen (torque sensing) is a gear driven type of limited slip differential that doesn't use clutches. The "Posi" or Posi-traction was a descriptive name invented by GM for marketing the limited slip differential option over the standard open case differential; this can include the Torsen. In other words, the term "Posi" refers to anything other than the non limited slip (open case) differential.

I'm pretty sure you aren't asking if people prefer limited slip (LSD) over open case so I'm thinking you want to know something like if they prefer the Zexel brand name torque sensing LSD or the Auburn Cone clutch type LSD. I don't know how many brands or types of limited slip, gear locking or torque sensing varieties have been offered so please don't take my response / question as though I'm an authority. I just keep seeing your thread and thought to add to it.

I like my Zexels because they simply work with no issues. I liked my Auburn until it wore out. The difference between the two is the Auburn will begin to lose the ability control limited slip whereas the Zexel either works like new or it is broken.

I will take the LSD (not the hallucinogen) any day over the open case differential unless I have little money. If money is not an object then I will take an Eaton.

**9t8z28** · 01-02-2007, 04:27 AM

Originally Posted by 01Z28M6

I'm trying to understand what you are asking. It's an interesting thread.

The Torsen (torque sensing) is a gear driven type of limited slip differential that doesn't use clutches. The "Posi" or Posi-traction was a descriptive name invented by GM for marketing the limited slip differential option over the standard open case differential; this can include the Torsen. In other words, the term "Posi" refers to anything other than the non limited slip (open case) differential.

I'm pretty sure you aren't asking if people prefer limited slip (LSD) over open case so I'm thinking you want to know something like if they prefer the Zexel brand name torque sensing LSD or the Auburn Cone clutch type LSD. I don't know how many brands or types of limited slip, gear locking or torque sensing varieties have been offered so please don't take my response / question as though I'm an authority. I just keep seeing your thread and thought to add to it.

I like my Zexels because they simply work with no issues. I liked my Auburn until it wore out. The difference between the two is the Auburn will begin to lose the ability control limited slip whereas the Zexel either works like new or it is broken.

I will take the LSD (not the hallucinogen) any day over the open case differential unless I have little money. If money is not an object then I will take an Eaton.

No offense taken. My question was wether to use the factory setup out of the 98 or the factory setup out of the 97? I really did't know what the reputation was of the Zexels.

**01Z28M6** · 01-02-2007, 05:41 AM

You are right that I didn't mean to offend and it's to your credit that you first assumed I meant no offense. Thanks.

Because I "think" 98, with the LS1 in the camaro, was the transition year. When GM went to the Zexel Torsen from the Auburn Cone, at least in the camaros, your question makes perfect sense. The Torsen style differential is considered an upgrade and from my understanding is more durable. Auburn has a pro series that beefs their unit up and adds some warranty so it may be a coin toss if choosing between the two when replacing but I thought it was generally agreed upon that the latter iteration in rear ends was an improvement.

I replaced the Auburn from my 95 Z28 with a Torsen unit out of a 2000 model. It seems to work perfectly but visually you will still see the one wheel peel. If it were the Auburn doing that it would mean it was worn out. When the Torsen does it, it is just the nature of the mechanism. I believe the one tire mark from the Torsen simply means the other wheel is exactly on the verge of spinning too. Regardless, the car fishtails under hard acceleration which tells me one side and then the other are vying for maximum torque. In other words, it is still working.

Here's an interesting link. If you go there, read to the bottom where the LSD names have evolved.

http://en.wikipedia.org/wiki/Limited_slip_differential

**9t8z28** · 01-02-2007, 05:48 AM

You could not have said that any better! And I am pretty sure that 93-98 was an Auburn, 96-97SS was a Torsen, and 99-02 was a Torsen. Correct me if I am wrong. Thanks for the help!

**Dillard99** · 01-02-2007, 02:25 PM

Hey thanks for your info, I have a 2001camaro Z28 Ls1 6spd, sorry if I was'nt clear but was wondering if the the eaton posi unit (Clutch type) was any good. I hear that the rear ends on the camaros does'nt hold up to well so was wondering if I up grade my gears and etc.would hold up or not. Looking forward for future upgrades Maybe about 400+at the wheels so just need info on what setups I can do now dont have the money now for a 12bolt or 9" so I want to beef up my 10bolt

**AKIRA** · 01-02-2007, 04:42 PM

Interesting last question.

I am pretty sure the clutches have worn out in my car. I remember hearing my mechanic saying it years back... I am dropping my car off tonight to get some subframes welded on tomorrow, but I also wanted him to find out why I hear a "howling" coming from my drivetrain. So it may seem like I will have to replace something.

Questions...

If your clutches in the rear wear out, then does only one wheel spin?
Does having one wheel spin hurt acceleration drag wise?
Does ANY of the shit covered in this thread have to do with gears? (chance of replacing them)
Eaton & Auburn = clutch?
Powetraxx & Torsen = torque?
Clutch or Torque, is one more noisy than the other?

**9t8z28** · 01-02-2007, 05:20 PM

1st question-If the clutches wear out, Yes, one wheel will spin. You really notice when you go around a sharp turn, both wheels should slid out but one spins and the other does not.
2nd question- My car when it accelerates from a stop, gets all over the place. So yes it hurts acceleration.
3rd question-The inital question was about the differential. Sounds like your rear is howling because where the gears contact has excessive play or you could have a loose pinion. Is the pinion seal leaking.
As for your other question I will let someone else jump in cause their close to my initial question.
Don't quote me, this is my opinion to the best of my knowledge!

**01Z28M6** · 01-02-2007, 09:38 PM

If you have an Auburn cone you can test it.
http://www.auburngear.com/aftermarket/faq/#q8

The Eaton is considered by many to be the best of the bunch. I would want it before the others. It's not only heavy duty, it can be rebuilt.

Howling can be caused by a number of things. The first that I would look into would be a wheel bearing.