hey guys i have an 86 iroc-z with 305 tpi with 700R4 auto, 4 wheel disk breaks.... and when i drive it when ever i punch it... it will walk side ways with ease.... im told that there was also a posi option for m car and im pretty sure i must have that option with how it acts... but just to make sure ware do i look can i tell from the VIN or that little paper on the inside of my middle console with the codes all over it? im sure it is but beofr ei go around bragging that my car has factory posi i want to know for sure... but every time it does spin the tires it is alwase posi and walks side ways lol im not complaining i love it i just want to know for sure.

 

Can we make a sticky about this topic please? It comes up just about every day.

The answer your looking for is this:

Pop the cover and look, you might as well change the fluid anyways. The RPO code can be inaccurate because most of us are not the original owners and items could have been replaced. The only true way to know is to pull the cover.

 

Agreed. There are other ways to tell too, but they are not foolproof and they are not always accurate either.

ie. If it leaves two stripes when you get on it, its got a posi - not true. My car has no posi, but it lights up both tires 99% of the time.

 

no need for a sticky, all we need is a full page sized one of these

 

i know this might be a crazy idea but pulling the cover on the rear might be a good way to tell if it's a posi or not

 

i just wanted to know how to tell if my iroc came with a factory posi all stock from the factory with out having to take anything apart.

 

jack up the rear so both tires are off the ground, put it in neutral, spin one tire, if they both spin the same way, you have factory posi, if they spin in opposite directions you dont. (also if you have posi one may spin and the other wont).

 

Or it may be you have a posi but its worn out, thats why the only way to know is to pop the cover. Were not trying to rag on you, just understand this comes up just about every day and if people would do a quick search they would find thier answer much faster.

 

to know what it left the factory with check the RPOs. won't tell you much about what it has now.

 

ware do i look for the RPOs are they all those codes on that piece of paper in my middle console or is it in the vin number?

 

The "codes" won't tell you what's in it now.

Take off the cover and look. It's the only way to be sure.