dumb question i have 2001 z28 and my friend said it doesnt have posi but i thought all v8 came with posi?

 

It should ....torsen i do believe just open drivers door look at the build sticker. If you see the code G80 then you have posi/limited slip.

 

Well I don't know about the 98-02 cars but I know the 82-92 V8 cars did not all come with posi. Of my 4 I own now, only 3 have posi. My 89 formula with the 305 only has limited slip.

 

All 4th Gen V8's left the factory with a limited slip differential. GM calls a limited slip differential "positraction". They are the same thing.

 

Then why do my cars have 2 different codes. 1 for limited slip and 1 for posi.

 

He said "all 4th gen V8s". 3 of your cars are 3rd generation.

 

Post the codes, and we'll look them up.

And it has nothing to do with whether its a 3rd Gen or a 4th Gen. I'll go back to the first GM car I bought brand new with a limited slip differential. It was a 63 Impala 300HP/327ci, 3-speed manual trans. It had only three options on it - a 3.36 limited slip "Positraction" differential, an AM radio, and HD suspension. Then there was a 66 GTO, 389 Tri-Power with a 4-speed. I order it from the factory with a limited slip differential but at that point only Chevrolet used the trademark "Positraction", Pontiac called it "Safe-T-Track". We could go on, but you should get the point.

"Positraction" was a GM trademark for a limited slip differntial. It was shortened by the gear heads to "posi". Traditionally, is was a clutch-type limited slip, but as you can see from a comment above, in the 4th Gens a Torsen gear-type limited slip differential was used.

Post your codes.

 

1989 formula 305
GU2 = axle rear, 2.73 ratio
G86 = axle, limited slip

1989 formula 350
GW6 = axle rear, 3.27 ratio
G80 = axle positraction, limited slip
G92 = axle rear ratio, performance

1992 z-28
GU5 = axle rear, 3.23 ratio
G80 = axle positraction, limited slip
G92 = axle rear ratio, performance

2001 ss
GU5 = axle rear, 3.23 ratio
G80 = axle positraction, limited slip

 

Your right has the code g80 thanks great to know

 

But it clearly indicates, per what you just posted, that G80 positraction is a limited slip. One code G86 for a limited slip that for some reason is not called positraction, and another code G80 for a limited slip this is called positraction. They are both limited slip.

 

I'm not saying a posi is not limitied slip. What I am saying is that you can have limited slip with no posi. Only one wheel on my formula 305 will drive at one time not both, with the passenger side being the primary drive wheel.

 

Then your limited slip differential is worn out.

By definition, positraction is the GM trademark for a limited slip differential. Has been for 50 years.

Go to the bottom of this Wikipedia article:

Limited slip differential - Wikipedia, the free encyclopedia

Or, from howstuffworks:

http://www.howstuffworks.com/differential.htm

 

Well then that could clear up a thread I started about 2 years ago. I'm not fixing it because it's only my work car and let's just say there is not much left to the body, but the drive train is in perfect condition. Not much longer and I'll have a fred flintstone car.

 

your axle is shot. even on one without limited slip, both wheels get equal torque. there is no "primary drive wheel"