Ok i have a 4th gen 10 bolt from an LS1 car... Zexel Torsel unit with 3.42 gears. I noticed the other day the rear end was making some noise when pulling out from a stop and turning at the same time. Rear end would pop/bang kinda sound, but only on slower speed tight turns while moving from a stop. (My 9 bolt did this and it was due to a broken spider gear) So i jacked up the car, put it in neutral and started moving the tires. Here is whats happening..I think something is broke but want to know before i swap rears. When I turn the driver side wheel forward, the passenger wheel will spin in the opposite direction for most of the revolution, but will sometimes stop for a second and then start to reverse rotate for alittle then go back in the other direction. Sometimes it will move very slowly in the opposite direction but not at same speed as driver wheel When I went to the passenger side and moved it backwards, the driver side did go forward When i turn the driver side wheel backwards, the other wheel moves opposite way (forward) (occassionally both wheels locked up and moved same direction but hard to spin) BUT when i move the passenger side forward I would expect the driver to be going backwards but it doesnt move...tries to but doesnt sometimes. I would have thought turning the driver wheel would always result in the passenger moving opposite and vice versus... but does the Torsen work in this manner? Kinda hard to explain i guess, you have to try to visualize it

sounds like something is definalty broke, or on its way out.

For what its worth, i have a tru-trac, similar idea to the torsel posi. If i turn the driveside wheel, with the car on jackstands, the passengerside wheels turn in the same direction.

mine seems to be working kinda funky but i was told its normal for a zexel torsen...

i took the diff cover off, had to peer inside to be sure of any problems even tho i didnt want to do it.

Found out i do have a chipped worm/spider gear in this unit... small chip on the tooth but probly enough to cause that binding/popping on certain turns... i dont think that effects posi function all that much but i think i'm gonna try it out this weekend at the track and see if it holds.

I mean it only does this on slow very tight turns and while on the gas, it was still spinning both tires very violently Eh, give it another shot i guess. i want 9's on a 10 bolt

That sucks man, bet it'll be tough to find another ls1 rear!
For the tire spinning thing all open diffs, will spin in opposite directions when you turn one. I know that some posi should make the tires turn in the same direction. I also have seen them spin in opposite direction when the posi unit is wore out, I have no knowledge on the torsen unit, but if it is a discs type posi,the discs may be worn out.

i can pick up 4th gen rears for cheap.. 100-150 without brakes ready to go in. Just take the brakes off mine and should be good to go. If desperate i'll take the rear out of my daily driver 99 trans am

Haha. that's good you can pick them up cheap. Sounds like a good deal. Just wondering where you get them from? A junk yard or other means?

yeah local fbody shop that has many 4th gen parts from buying and selling wrecked cars and such.

I decided not to try the 3.42 rear this weekend, i looked at the insides the the chip on the worm gear was very bad and causing it to slip/jump over teeth. I dont need that, so i got another 2.73 rear from a 4th gen for 60 bcuks that had low mileage from the looks of the internals and did the swap