Did all Z28s in 1985 come with a posi carrier?

 

No

 

It Was An Option.

 

Thanks. My 85 Z28 finally arrived yesterday and I have been eyeballing the options listed in the console. Does the axle codes appear anywhere other than on the differential?

 

You should have a RPO code stating posi/non posi, and gear ratio.

 

RPO code for posi is G80.

The one that would have come in it, would have been an Auburn. A steaming bucket of spit. Odds are, even if it came with it 32 yrs ago, it's not working now.

And of course anything could have got changed over the years; and more often than not, IF YOU DON'T PHYSICALLY LOOK AT WHAT YOU'VE ACTUALLY GOT, anything you buy for it will be WRONG. Parts are funny that way... seems like they have an ability to invalidate whatever you do, if you "assume" anything.

Since you just got the car, and you seem like a reasonably intelligent person (having had the smarts to find this site), then like any other reasonably intelligent person who just bought AN ANTIQUE CAR, the VERY FIRST THING you're about to do, is change all the fluids. For the rear, ya gotta pop the cover off ANYWAY to do that, so instead of posting on the Internet, LOOK at what's inside there. Whatever it is, is what the car has.

 

I agree with Sofa. I bought a posi-rear out a 40,000 mi 84 Z28 and its already not functioning most of the time.

 

What gear ratio does your car have? If it has a 3.23 to 3.73 then you can put in an Eaton Posi, Yukon or other limited slip differential. Just don't get the Auburn or Eaton Governor Lock.

 

Toms Differentials, is a highly recommended place to gain information and buy the right parts for your car.
Many of the members here have used him with great results.
= http://www.tomsdifferentials.com/

Here's my 10 Bolt Upgrade Thread. Love the Eaton Posi.
= https://www.thirdgen.org/techboard/t...de-photos.html

 

Before you buy ANYTHING from ANYBODY, take off your rear end cover and LOOK AT WHAT'S INSIDE. While you're changing out the fluid that's already 5 times as old and has 4 times the miles on it that it's supposed to.