also is it open, posi, locked, and so on. any help is well appreciated.


PS: (im new to thirdgens and im looking on making mine a quarter mile car so any other "oh btw's" would be appreciated too, i dont know much but im learnig.)

-kevin

 

Hi Kevin, welcome to the site.

Check your RPO codes which are located on a sticker in your center console (if it's still there.) Below is a breakdown of the 10 bolt RPO's which was ripped directly from the sticky at the top of this forum.
2.73 (RPO GU2)
2.93 (RPO GU3)
3.08 (RPO GU4)
3.23 (RPO GU5)
3.42 (RPO GU6)
3.73 (RPO GT4)

I believe every posi was denoted by RPO G80. Third gens never came with lockers from the factory. A fast way to determine whether or not you have posi is to do a brake stand and see if you leave one or two black streaks behind. If you leave one, open (or burned out posi unit) if you leave two, posi.

 

If you're uncertain of when the fluid was last changed (or if the rear is original to the car), now's the time to drop of the cover, take a peek at what the rear is equipped with, and change the fluid. There are pics/info in the 10-bolt sticky at the top of the page. BTW, it could be that your car is equipped with a 9-bolt.

JamesC

 

well yes iv done break stands and only one wheel spins... most of the time. but others both will. so im guessing my posi is worn or wearing? but ether way how would i go about getting a locked or "locking" my current rear end?

 

Changed the fluid lately?

I suspected not.

While you're catching up on the overdue maintenance, make a point of LOOKING AT THE PARTS. Whatever gears you see in there, that's what it's got. If you see a posi, it has (or at least at one time "had") posi; if not, it doesn't.

None of us out here can do anything better than just GUESS at what's in that rear. Although if it's the one that came in the car, a good "guess" would be 3.23, non-posi. At least, I think LB8 is a 6-cyl... isn't it? I have not the vaguest clue about those.

 

unless it has been changed, its a 3:42 open rear

 

sorry guys i see that i asked you what my rear end is without even telling you what car; but i see that you fiquerd it out. so i guess we've came to the conclusion that the OE rear end on a 1986 firebird 2.8L is the open 3:42?? and sorry i just got the car off some guy and im just trying to get some basic info on it. and yes like you said catching up on some maintenance... lots of maintenance. so im getting to that side of the car when i can^