I have bought a rear end from a 89 Iroc complete with disc brakes LSD and 3.73s and I want to swap it into my 92 RS as it has none of these. Is there any articles available on doing this swap and is there anything I should know or need about this?

 

if you have the complete rear; brakes, all brake lines and parking brake cables, its a complete bolt on job. Just remove what you have and replace with the new rear, then bleed the brakes.

Probably an article somewhere, but its not rocket science. A air compressor and a 1/2" impact gun with sockets will help a lot, especially if you old rear is a bit rusty.

Jack up the rear of the car and support the car by the "frame" just inboard of the rear control arms works well, as well as just ahead of the control arms. with the floor jack supporting the axle, take off the wheels,

-unbolt the shocks

-detach the flex brake line at the body or on the "t" block on the axle, this would be a REALLY GOOD TIME to replace all the brake flex lines with earls braided stainless ones. Front and rear. 5 lines total for a 4 wheel disc car.

-remove the panhard bar

-remove the driveshaft, if possible do not pull it out of the trans or oil will probably spill everywhere.

-remove the parking brake cables form the tunnel pulling assembly, they are different for a disc rear.

-lower the rear as far as you can, be sure nothing is hanging up on it, brake lines ect.

-remove the springs, they should come loose in the pockets, keep track of the upper insulators, they may stick in the spring pocket. you will need to re install them later.

-remove the lower control arms.

- you should be able to pull the entire rear along with the torque arm out of the car, with the axle sitting on the floor jack.

-reverse this to install the new one.

-now the fun part, go back to the car that you got the rear from, if you got it from a car, and get the proportioning valve too. Its the blocky looking thing under the brake masted cylinder with all the brakes lines running into it. Or buy a new one form the dealer $$$$ or ebay/craigslist/ect. This should be done for the rear brakes to work the best.

-I know the was a redesign in the parking brake cables in the tunnel in 91-92, im not sure what it is exactly, but i dont think it will affect the installation of the earlier cables, might want to look into this a little further

Just make sure the front wheels are blocked so the car does not roll and the car is supported in the rear by a set of good jack stands.

I think this covers everything, just keep track of the bolts you remove, spend a couple bucks for some new rear shocks if they are still original or old, and like i mentioned before, swapping in braided flex lines would be a good move too.

Any questions, just ask
later

-phil

 

If you bought a 89 IROC rear it is in most cases a 9-bolt. Still no big problems, it will swap right in. But you will need the Proportioning valve and the Parking brake cables for it.

 

The Proportioning Valve will look the same, but it isn't.

Yeah if you don't get the Proportioning Valve you won't get enough fluid to the rear disk calipers. Drum PV wont produce enough pressure. The drum has a smaller cylinder than a disk caliper.

 

Or if you can't get the prop valve, get an adj valve, and follow the steps to adjust it properly.

Or are you guys talking about the prop valve on the rear axle that balances left/right back there?

 

The prop valve is located under the master cylinder in the engine compartment.

 

Thanks guys please keep the good advice coming. Is a 9 bolt better or worse than 10 bolt?

 

The 9-bolt is way better then the 10-bolt. Just don't abuse it, because parts are hard to find. Nothing to worry about though.