iroczman380

Hey!!! I need your help, I have a 1986-almost 1987 Iroc-z28, with Posi traction. I called chevy, and asked them how many splines my rear axle had, and they could not tell me. I got the casting number off the housing. It is 22522676. No one knows!!! Its ridiculous. My car has posi-traction stock. And its a 700r4 auto. Does anyone no, what I need to do to, I would like to swap my gears to 3.42's. I dont know what I need to do though except for buying the gears. But I cant even do that without the information. My car is also a 10 bolt. I dont know if I need an installation kit, or what, Do I have 26 or 28 spline??? I have all these questions and no answers!!!! Please someone help !!! Id like to get this swap done but I dont no where to go from here!!! Please help, any info at all is appreciated, thanks

ede

spline count has no bearing on installing a ring and pinion or what you need to buy. you should have 26 spline axles in a pre 89 10 bolt. yes buy the install kit and find someone to put it all together for you.

RB83L69

You need to take the cover off and look, see what gears are in it now.

If they're 2.73 or 3.08 (could easily be), then your carrier is a 2-series, and you'll either need the special thick 3-series gears to go on it, or a ring gear spacer to move the ring gear over to where it will touch the pinion. If they're 3.23 or higher, then you won't notice much difference going to 3.42s; but they'll bolt right in.

If you have the stock 86 rear end, it will have 26 splines on the axles and the side gears in the carrier.

The casting number of the housing is completely useless for identifying anything. All that means is that it's a 7½" 10-bolt center section, with the torque arm mount cast onto it, so it's for one of these cars. It has nothing to do with what yerar it is, what the axle splines are, what series carrier it has, or what gears are in it.

Take off the cover and look before you buy any parts. People swap stuff all the time, and what your "codes" say is in it, may or may not be accurate, and there's like nothing worse than having some expensive part that you just busted open and installed halfway and now can't return, that doesn't fit whatever is inside your housing.

Oh, in case I forgot to mention.... take off the cover and look at what's inside your rear end.