Gears & Axles - My Eaton (12 bolt) tries to do 1 wheel burnout - possible?

Yesterday when I was doing burnout at the strip I was told my right wheel did not turn at all. I only had 1 pass so didn't understand much, but while doing it, I felt as if the car was "swinging" or leaning from one side to another as if it was spinning one wheel and then the other and again.
We tried to do it this evening and noticed both wheels don't spin simultaneously - it looks like both wheels spin up, then suddenly wheel stops for a split second and then spins up again. As if the power was alternating between wheels. Feels inside like something is "switching" in the rear. But it's not always acting the same.
This is 4L80E in a turbo LS1 if that matters.
I hope this makes any sense to you? What is this issue I'm having?? Or is it just normal for Eaton (I was told it is Eaton - it was there when I got the car).

Here's how it looked inside when I had my wheel studs changed

What type of Eaton is that?

It does not look like an Eaton HD Limted slip.

http://www.drivetrain.com/images/stories/product_imgs_large/eaton_posi_image.jpg

Maybe a Trutrac? They have been known to be fragile if it is. If you have any power at all with the trubo, you are well beyond a Trutracs limits.

http://static.summitracing.com/global/images/prod/large/dtl-912a310_w.jpg

previous owner says it's Eaton, with 33 splines...

does your posi have springs like this on the other side?
http://www.expeditionexchange.com/sema2002/DSC01943.jpg

does your posi have springs like this on the other side?
http://www.expeditionexchange.com/sema2002/DSC01943.jpgHonestly, I don't know, we didn't rotate it to see that...

Eaton has a few different models , including the TruTrac listed. My gut says you have a trutrac, but the E Trac looks similar.

http://www.eaton.com/Eaton/ProductsServices/ProductsbyCategory/Automotive/AutomotiveAftermarket/Differentials/index.htm

Each model would have different symptoms. You need to figure out what you have first.

Just found this picture of a Trutrac.

99.9% sure you have a Trutrac.

http://www.firebirdnation.com/forums/uploads/1266690918/med_gallery_9104_7_1321530.jpg

If I recall they say the Trutrac can be ok up to about 400rwhp on an M6 and I would guess on an auto it might be ok up to 450-500.

If we decide that it is Truetrac, why it could sometimes do 1-wheel burnout? Any way to cure it?

A Trutrac is supposed to act like a locker when it engages. They mechanically lock when the torque load on the axles are different and act like a open rear at easy driving around town use. Does yours make any bad sounds when you are going around turns? If it was broken to the point of not working correctly it would be crunching and banging. I'd say a one wheel peel with a Trutrac is not a good sign.

Pretty sure that the Trutrac was not rebuildable. The Eaton HD was, but that does not look like a HD. I used to have a HD and you could see the springs and clutches in the big side window.

If it is pooched, you will be looking for a new one. Do not buy another Trutrac.

Look at an Eaton HD, S Trac, or Wavetrac. The last 2 are a lot more money.

A Trutrac is supposed to act like a locker when it engages. They mechanically lock when the torque load on the axles are different and act like a open rear at easy driving around town use. Does yours make any bad sounds when you are going around turns? If it was broken to the point of not working correctly it would be crunching and banging. I'd say a one wheel peel with a Trutrac is not a good sign.No, doesn't make any bad sounds at all.
When we tried to do few wet burnouts at the street, it spinned both wheels, but one of them sometimes stopped, I described that in more details in the first post.
But in my only one burnout at the strip, I was told that 1 wheel was not spinning at all...

Trutracs are a torque bias diff, similar to a Torsen, Wavetrac and S Strac. The last two being very strong though. They do not lock up like a locker.

The only thing you could try is drain the fluid and put a conventional oil that has no friction modifier in it. It might cause a little more bias offering a better chance of both wheels spinning.

Rampant is right, Eaton does NOT recommend synthetic oils be used in the rear with a truetrac. Scroll down this link for truetrac FAQs http://www.eaton.com/Eaton/ProductsServices/ProductsbyCategory/Automotive/AutomotiveAftermarket/Differentials/FAQforDifferentials/index.htm
Does your car lay two stripes on dry pavement?

Yes on street tires it leaves 2 tracks.
So, we have concluded that I have Truetrac, right? And that it is probably worn?

After reading the net some, I was wrong above when I stated the truetrac acts like a locker. In situations of marginal traction the truetrac transfers torque back and forth across the axle to the wheel with the most traction. When provoked farther with increased throttle then it solidly spins both tires. Also googling one wheel burnout, seems other people are reporting the same one wheel alternating burnout as you. One guy says to jab the brake when it's doing this and then it should start spinning both wheels.
http://www.novas.net/forums/archive/index.php/t-6746.html

You might want to call the Eaton Tech Line and see what they say.
I'm tending to think it's OK, just need to learn the right technique with the water burnout.