I recently got a 4th gen rear to put in my Z. I got it out of a 00' 3.8 its a 3.42and I'm 90% sure its a posi. I have to tear it down to get one of the tubes straightened and was just wodering how you can tell if it needs a rebiuld and if you can even rebiuld these things. It has 80K miles on it

 

Those don't need a "rebuild" like older posi systems do. They use worm gears rather than clutches.

So basically, as long as the bearings run smooth and the fluid shows no evidence of metal shavings or other death, it's good to go.

I'd be a bit concerend about axles and axle bearings though, if something happened to it hard enough to bend it.

 

I work at a shop in Nashville and one of the body shops we do alingments for brought the car in for us to swap in a totally new rear so i told them "don't worry I'll throw the old one away for" . the car was hitin the left rear and bent the tube up a degree the car was towed on a flatbed to our shop so i don't think it caused too much damage, but like i said i have to tear it all the way down to get the tube straightened so i'll be putting new bearings and seals in it.
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does it sound odd for a V-6 to have a posi. or were all 4th gen rears