supersickss

ive got a question did all 98+ camaros come with the Posi or was that just an available option? ive checked the codes and it says i have it was just wanting to know if everyone else has it as well

jmdale1984

iTrader: (6)

Umm... to the best of my knowledge, no 4th gen fbody came with a posi. A different limited slip unit was optional for 97-98, and standard for 99-02 SS's and Z28's, but I believe that was the best option. If you have a posi, (someone correct me if I'm wrong) it's aftermarket.

jimmyblue

iTrader: (11)

V8s ('98-up anyway) all got some kind of traction rear
end, most of them the Torsen which is not strictly a
Positraction, some an Auburn which is a friction type
like the GM Posi but cones instead of plates. V6es I
believe did not, don't know if it was even optional for
them. A Torsen may not give you the outward signs of
a hard-locking differential because the stock Torsen
can only split so much torque before giving up and it
is less of a split than the difference between tires'
stuck and spinning friction. Still 3X spinning thrust is
better than 1X (open diff) aside from the fact you
are making shavings out of the Torsen metal every
time you do a one-wheel peel.

supersickss

i read the codes on my car and it says Posi ( limited slip). since this is a code on the door i assume its not an aftermarket piece. its a 2000 z28 so wich would that be ?

jmdale1984

iTrader: (6)

I'm sure it's the Torsen (mechanical)... don't get confused though, it's not posi. Should spin both wheels regardless.

supersickss

well how do i find out for sure

jmdale1984

iTrader: (6)

Pull the cover... look inside the carrier... if you see gears, it's Torsen (mechanical)... if you see springs and bright colors, it's Auburn. I read somewhere on here that the Auburns tend to handle more power before the break something... and you just may have a chance of not breaking your 10 bolt with an A4.

monzaz

You guys use that term posi (positraction) Which has loosely become a industry standard because it is nice and short and most people associate it with a EATON positraction unit installed in CHEVY muscle cars way back in the muscle car days... Which was and still is one of the best limited slip designs out there. This is CHEVY's pet name...term... nickname etc. for limited slip differential. Pontiac had their term, sure trac and mopar had suregrip and Ford trac lok or something and so on ALL LIMITED SLIP UNITS/DIFFS. Any unit that delivers and or locks both wheels in a mechanical fashion and releases for turns in some percentage can be considered Limited slip differential unit. examples (Eaton, Auburn, Power Lok, even Torsen. It is limiting how much grip or slip the vehicle gets in a certain road situation... be it - turning a corner or ice, mud, gravel etc. It will deliver power in a percentage to the wheel that needs slip or grip according to the way the unit is designed. Torsens and true tracs use a series os sliding helical shaft gears to get the job done ...while Eaton and Power lok units use a series of clutch discs and preload springs...then there is Auburn which uses 2 conical side gears into the machined case with preload springs to do the same thing. All work well and provide lock up in straight line situations.

Even the eaton style govenered lock up clutch type units are a limited slip unit which alot of people consider LOCKERS. These units also use a series of clutch packs so even though they mechanically lock and unlock with the govener set-up they will slip in a corner when locked because if they do not the axles will bind and your truck would bounce and shimmy around corners and tear up axles an dmight even snap one... if the unit does not blow up first....lol. THis has to be for saftey reasons ... at least from the factory stand point. Aftermarket anything goes.

Mini spool is a direct lock up and will never unlock. It would be as if you welded the spider gears solid. Same as a Full spool but no ring and pinion gear swap/change is required in a mini spool. Mini spool is just the spider gear swap out.

Power trax no slip (LA LOCKER) are detroit locker type units in mini form...kind of the same relationship a spool and mini spool have to each other.
Power trax units:
They are locked down hard on acceleration as the pinion shaft trys to force its way through the unit creating side load pressure to the engaged teeth locking them up hard and in turns axle bind (twist ) to a certian percentage then the units two machine meshing teeth slide over each other by again over coming spring pressure (like in a limited slip diff unit) to slide to the next tooth around the diameter of the side gear and locks back into a slotted tooth again (lock right units). This happens till the full turn is completed and then on the straight away will be locked once more. (power trax No slip units) from Richmond have improved the sytem a bit by taking it to one full tire revolution before locking back into a tooth again. This limits the number of rachets needed in a turn which in turn cuts down on clicking noise and wear.

Hope this helps everyone understand limited slip units and the term positraction a bit more and where it came from and why it is used as a slang term.

I am sure that all the this not 100% to the 'T' and someone will find some flaw in spelling and or other tid bit data left out...I have been building diffs for a while now and you can be pretty confident about the info. If you need any other questions or info on them please ask if I know it I will tell you straight up if not I will help find it and if I do not know I WE SAY SO...no BS answers here.

Take care, Jim J D Race and Restoration

www.jdrace.com

alamantia

iTrader: (10)

Jack up back of car, release e-brake put car in park (Auto) or in gear (manual) try and spin the passenger side rear wheel forward, if the drivers side rotates the opposite way, its a torsen, if you cant spin the wheel at all its an Auburn, take the car out of gear and spin the passenger side wheel forward and you will see the drivers side spins the same direction.

jmdale1984

iTrader: (6)

Learn something new every day.

supersickss

wow thanks for the history lesson thats good to know and same to you alamantia they should post that in a sticky, sicne i seem to see alot of people ask that

Sideways240sx

iTrader: (22)

So. Which rear end is harder to install a gear in? Auburn or torsen? are there any more needed parts if you have one rear end or the other?

I have a 98 ta, and im gonna jack up the rear, and find out if i have an aubrun or torsen, but i just got the gm 4.10 with the motive master install kit, and all the fluids i need. Im gonna try and start the install this weekend, and if i need any extra parts, or i have the wrong stuff, id like to know in advance. Thanks, Chris

alamantia

iTrader: (10)

Torsen uses a thrust block or "paddle" to retain the axles, Auburns use a cross pin. Torsen paddles will get hung up on the ring gear of 4.10's not allowing it to slide back in, you can invest $$ in SLP's paddle kit or simply grind off a small chamfer on the portion of the paddle which interferes with the ring gear. I have done a rear where it didnt need to be ground off and I have done two which needed it. If you have genuine AAM 4.10's backlash can be set as low as 0.005" if they are motives 0.010" is optimal. Because of the small diameter of the pinion in 7.5 4.10's there may be some whine around 60mph. I have had more luck with a quiet rear using AAM gears but i still get a little. I should have brought it to a reputable shop instead of doing it myself in retrospect, they have way more experiance lashing gears than i do, something you may want to consider if you dont have a ton of experiance swapping gears or this is your first time. I think its good to DIY and learn but if nouise bothers you like it does me, eh, maybe you want to look into a shop... just my $0.02 but hystory has proven i dont know anything.

Sideways240sx

iTrader: (22)

i have someone helping me who has done several rear ends. just never on an ls1. i got the aam gear, since most say it will not whine as much. Id prefur to do it myself. Even if it means i screw up and have to do it again. Im the type that would rather learn what im doing, and whats going on, rather then just pay to have it done.


Thanks for the info though. Im hoping the car has an auburn since that should be the easier of the two since no paddles. I read someone post that unless someone changed the rear end all 98's had the auburn. I will find out soon. Thanks, Chris