Positraction

[Phlash_riot]

Ok heres the quick scoop
Got a 99 T/A... thought I had positraction... or what ever would have both tires turning and burning... recently found out that I have only one tire burning. Did a burnout only ONE mark on the road

Then i was in some snow I open the drivers door and give a little gas and hear on tire turning and the other is sitting there staring at my like a 3 toed sloth... What gives......

Do all T/As have posi and mines broken or is it an option.... and how do i get it in my T/A... I can't have this anymore one tire burning out... its sacrilegious!!!!!

[yellowv]

Ok heres the quick scoop
Got a 99 T/A... thought I had positraction... or what ever would have both tires turning and burning... recently found out that I have only one tire burning. Did a burnout only ONE mark on the road

Then i was in some snow I open the drivers door and give a little gas and hear on tire turning and the other is sitting there staring at my like a 3 toed sloth... What gives......

Do all T/As have posi and mines broken or is it an option.... and how do i get it in my T/A... I can't have this anymore one tire burning out... its sacrilegious!!!!!

Posi is a limited slip differential. It's not a locker. They both aren't gonna spin all the time. Hence the term positraction. The differential will apply more power to the wheel with more traction.

[Phlash_riot]

i know how both work but that is not happening on mine... If one wheel is spinning an the other one is not then the wheel with mortraction is not getting any power otherwise it would spin as well... I belive that there are clutch discs in positraction so mabye the clutch went out on mine.

[yellowv]

The diff could be going but you were talking about spinning the tires in the snow. Will it only spin one on nice dry pavement as well?

[Phlash_riot]

yes.


i am making sue that posi is a standard feature too

[volleybill]

RPO G80, check your tag on the door

[Phlash_riot]

Thanks I'll look into that today when its daylight out. So i take it that it is not a standard feature

[z28misfit]

As far as clutches go, you most likely have the Zexel Torsion unit. I believe all the LS1 f body's have them. They don't really have clutches, I believe they are called helical gears. Let me know if I'm wrong on this. But anyway, I would think as long as it's good, it should let 2 lines when you do burnouts. I know mine has never left one mark.

[Wesman]

As far as clutches go, you most likely have the Zexel Torsion unit. I believe all the LS1 f body's have them. They don't really have clutches, I believe they are called helical gears. Let me know if I'm wrong on this. But anyway, I would think as long as it's good, it should let 2 lines when you do burnouts. I know mine has never left one mark.

Many of the earlier LS1's, like 98-99's, had the Auburn Differentials. They are clutch pack equipped, limited slip units. After a while the clutches wear out, and only one wheel will spin when you are trying to get traction. You need to replace the carrier with a new unit in order to fix it. Ideally, a brand new Auburn will lay down 2 strips of rubber on a hard launch, so its a real posi.

Later LS1's were equipped with the Zexel Torsen units, which, like you said, don't have clutches and therefore can't really "wear out". The performance of the Torsen, provided it isn't broken, will be consistant no matter how old it is. However, since it doesn't have clutches, it can only distribute torque to the wheel that has more traction, hence the name Torsen, or "Torque Sensing". So if even though both wheels will be getting torque, one will be getting more than the other at any given time. Hence, it may only lay down one strip of rubber on a hard launch. The other disadvantage to the Torsen is that if one wheel has no traction (ice/snow) the car won't move. Both wheels need to have at least some traction for the diff to work properly.

As for determining which diff you have, perhaps someone else has some insight on that. I don't know how to specifially tell the difference between the two.

[z28misfit]

I know I have the Torsion model. I do know the LT1 cars have the Auburn.

[9t8z28]

93-98 Auburn
96-97SS Torsen
99-02 Torsen

[Phlash_riot]

Well I still have yet to check out my RPO code but i everything above holds true looks like I have the Torsen unit.

So here's the new question... I want a differential that spins both tires no matter what. ice snow burn outs i want both giving me traction. no the possibility of both. Wha shoudl i get? in a 10 bolt, I'm not swapping out to a 12bolt . soon as the new Camaros come out (and are avalible to get due to demand) i'm trading the bird in.

[Wesman]

Well I still have yet to check out my RPO code but i everything above holds true looks like I have the Torsen unit.

So here's the new question... I want a differential that spins both tires no matter what. ice snow burn outs i want both giving me traction. no the possibility of both. Wha shoudl i get? in a 10 bolt, I'm not swapping out to a 12bolt . soon as the new Camaros come out (and are avalible to get due to demand) i'm trading the bird in.

Look into the Eaton Powertrax.

JEGS's sells them, heres the link:

http://www.jegs.com/webapp/wcs/store...44476_-1_10153

[pocheasy]

93-98 Auburn
96-97SS Torsen
99-02 Torsen

really the LT1 SS's got a different rear end then the 96-97 Z's?

[Firebirdjones]

I think positraction has been misunderstood over the years,,,posi has always been what GM referred to as a clutch style unit, both wheels will spin all the time,,,unless for some reason the clutch pack is weak or worn.
At some point in time, people started referring to positraction as a limited slip, or one wheel spinning most of the time. Simply not the case.
Limited slip, positraction, both mean the same thing among most car enthusiasts, both refer to the clutch style unit that GM has used for years.
In a slippy situation with one tire on ice or snow,,,technically a clutch style unit will pull you right out without spinning the one tire in the snow, utilizing the tire that is on the pavement, the tire in the snow cannot spin unless the power applied overcomes the clutch packs in the posi unit. Only then will the tire in the snow spin,,,,once this happens it puts some wear on the clutch packs,,,the more you do it,,,the more it wears. After a while the clutches are worn to a point where they are not that effective anymore. They are made to slip to some extent for turning obviously.
You can check the condition of the clutch style posi unit,,,this comes right out of an old GM manual I have in the shop.
Hold the pinion still with a prybar,,,I have a tool that bolts to the yoke. Using a torque wrench on one wheel,,,either side it doesn't matter,,,try to turn one wheel while holding the pinion still,,,sometimes this takes 2 people.
GM has a torque reading specification,,,at the point in which you can break the clutch packs loose to turn one wheel while the other stays still. I don't remember the number off the top of my head,,,,but I can tell you a good posi unit will make you grunt and sweat trying to turn one wheel. If it's rather easy,,chances are,,,,the clutches are worn.
You probably have the auburn style unit, which uses cones,,,these are not as durable, and when they are worn,,,generally they become a door stop. The cones wear into the case, and renders them useless. The case can be machined and the cones shimmed out,,but it's a bandaid.
Go with the Eaton unit,,,clutch style,,they are rebuildable with various kits you can tailor the preload on the clutches to the point where there is virtually no slip at all, and can even chatter tires around corners if you like,,,these are what I use to get around in the snow and they work flawless,,,as long as I can get one rear tire on dry pavement,,,it will pull me right out of the snow without problems.
As far as I know,,,,All T/A's came standard with posi,,,this is how it was back in the day throughout the 70's and I don't believe that has changed. Chances are you have a wornout unit and it's time for a replacement. Larry.

[LS1Formula01]

Long story short, all LS1 F-bodies have the torsen diff, which has a worm gear design, torque and centrifical force cause the gears to climb up another set of gears to engage the axles, one always turns, the gears in the diff have to engage to turn the other. I notice on take offs where i ease into the power its hit or miss as far as one or both engaging in mine, now when i rev up and dump it, both engage and smoke like cheech and chong.

[9t8z28]

Long story short, all LS1 F-bodies have the torsen diff, which has a worm gear design, torque and centrifical force cause the gears to climb up another set of gears to engage the axles, one always turns, the gears in the diff have to engage to turn the other. I notice on take offs where i ease into the power its hit or miss as far as one or both engaging in mine, now when i rev up and dump it, both engage and smoke like cheech and chong.

98 did not come with Torsen!!!

[LS1Formula01]

It was an option if i am not mistaken, buddy of mine has a 98 w/torsen. unless it was put in after the fact.

[AKIRA]

After going through my rear end bullshit, the differential I pulled out was a Torsen. We slid it onto an axel that was in a vice. My mechanic said that with one axle locked (in the vice), the differential shouldnt spin on the axle. It sure did.
We put the Eaton on in place of the Torsen and we couldnt spin it.

I didnt get the PowerTrax one but the Eaton (clutch based one). So far so good.

[9t8z28]

After going through my rear end bullshit, the differential I pulled out was a Torsen. We slid it onto an axel that was in a vice. My mechanic said that with one axle locked (in the vice), the differential shouldnt spin on the axle. It sure did.
We put the Eaton on in place of the Torsen and we couldnt spin it.

I didnt get the PowerTrax one but the Eaton (clutch based one). So far so good.

What do you mean?