Ok,

My buddy has a posi unit from his 83 trans am, he said it was a 3.73:1 posi unit, I'm pretty sure it was swapped into his car from a different car, I could be wrong tho, but hes just giving it to me.

So my question is, how hard is it to swap gears in the rear end? I've never done it before, and am not planning on just jumping into it. I'm assuming there shouldnt be a ton of extra parts to buy would there?

I dunno.. I guess just give me an idea of what im in for?

 

ok, I got a little more information about the posi.

its a auburn posi with richmond gears, I don't know anything about this stuff.. can anyone chime in what it would take to swap these in?

 

well all i know you have to align things correctly take out the drive shaft and change the u joints and all the seals.. my freind did it for free when he broke my 3.73 posi rear end... was pissed off... and he ended up ruining more then that... in the long term... but other that it just takes time....

 

3.08 to 3.73 requires a different carrier. I'd leave this swap to a professional.

JamesC

 

well.. im not dense.. I can understand how things work if its explained.. maybe ill just go buy a manual or something.

 

Me either--at least on a good day. The swap isn't something I'd personally want to be involved in, though it might be a good learning experience. Anyway, check the following link for an idea of the complexity:

https://www.thirdgen.org/forums/tran...+gears+setting

JamesC

 

The '83 will have 26 spline axles. I think you also have an '83, so this should not be a problem. The Auburn is my last choice for a posi becasue they wear out quickly and fill the rear end with metal. If this Auburn is not worn out then it would be worth the effort to change it. If it is already worn out then chuck it in the trash and get a new Eaton. To do this swap you must set the pinion depth, bearing preload and backlash. These must be set to within +/- .001 inch to be correct. This is hard to do with used gears becasue the contact pattern is harder to read because of normal wear. If the gears were set up correctly the first time then you have a chance. If they were set up wrong then they too are junk. This is much easier with new parts, but I understand that most people today can't go out and spend $800 on new parts. If you are getting these parts cheap enough and this car is not your daily driver then you don't have a lot to loose by trying it.

 

from the sounds of it, this posi unit is either new, or close to it, I don't know for sure, but my friend doesn't drive his car that often, he pulled the gears to put like 4.56:1 or something like that in his car, I dunno.

My car is just a project, I very much doubt that it will be more than a weekend car, my brother is a certified master mechanic, and he has any tool that I could ever ask for to work on this, he just doesnt have a ton of time to help me, if I do it myself, and I think I have it right, he would double check it for me, but thats about all he could do, that is why I'm asking, does anyone have a good site, or any idea where I can find exact steps on what to do?