cant u telll if the rear end is posi through the vin number? i know u can if the rear ends are posi on s10 trucks is through the glove box. but i want to be sure that the rear is posi cuz thats alot of work for it not to be and isnt mine posi? 88 trans am with a g80 rear its a 10 bolt. do they stop working after a while? cuz mine will spin the right wheel then if im turning left the other wheel will spin and the right wont.

 

Take the cover off and look.

 

what cover and where is it

 

The differential cover on the rear end.

 

If you have a G80 RPO code then it's suppose to be a posi, but if it looks like it ain't working then it probably needs rebuilding.

 

Easy way of testing for posi is jack the rear up, put the car in neutral, then spin one of the tires. If the other spins the same direction then you have posi. What you're describing when bruning out is exactly what SteelTownMadDog said, your posi is shot if you still have it.

 

not always the case i have seen posi rears do just the opposite. best way to tell is pull the cover if you see springs its posi, unless its a 4th gen zexel.

 

The only way to know 100% whats in there is to pull the cover!


RPO codes will tell you what it rolled out of the factory with 20 years ago and unless the car was shrink wrapped and in storage until now its very likely theirs something different in there.

 

I have a 9 bolt with the g80 and g92 options. I could not figure out why it's doing that. I even asked about it on here and people said it sounds like a normal 9bolt. And yes I pulled the cover to check when I did a fluid change. But it works fine. lol. Adam :-)

 

My favorite method of testing is to do a burn out in dirt
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Buy tires often do you?

 

lol you cant test them in dirt my open rear will rip them both in the dirt if i hammer it enough LOL

 

dirt is useless, except for getting your car dirty...


an 4cyl duke with an open diff spins both tires in dirt.

 

so if i do have a posi i should just change the fluid and it should work. or do i have to just go and get a new rear end? also where are the numbers im looking for at in the rear end itself or somewhere else and if ur theory is correct i can go to the junk yard and pop the rear cover off and if i see springs take it cuz its posi?

 

Easiest way to check is do a burnout... if you have the RPOs for it and it is leaving one leggers then you need to rebuild the unit..

 

pop off your diff cover if there is springs its posi. If theres no springs its not. Depending on the year of the axle its either 28 spline or 26. They are not interchangeable. look for a camaro with the same amount of bolts your cover has and springs inside. The trouble with j yard posi is you cant gurantee its gonna work. your best bet is to get a zexel off ebay provided you have 28 spline axles.If you have 26 you can just buy a 26 spline posi carrier. I think they started 28 splines in 89 if im not mistaken.you can always slide an axle out and count the teeth to be 100% positive while you have it open.

 

Not all posi's have springs. If you have a 10 bolt it will have springs if it is a posi. But 9 bolts have a cone type posi. The thing about 9 bolt's is I don't think they ever had a non posi 9 bolt. Adam :-)

 

There were non-posi 9 bolts.

 

LOL this thread should be called how not to tell its a posi. seriosly tho just follow Apeiron or my advice and you will be able to tell.

 

I wasn't to sure since the 9 bolts were used in the hipo f-bodys. I guess you learn somthing new everyday. lol. Adam :-)