Hi guys,
I'm looking to get rid of the rear drums in my 92 RS. I have a rear axle from an 88 Iroc. I understand that the gearings in the rear ends are different to handle the different motors, can anyone tell me if the axle's can be swapped right out? I'm looking to just take the axles off my 92 rear end and put the axles in from the 88 iroc.

 

Yes they can be swapped.

However the hydraulic requirements of the 88 disc brakes are CONSIDERABLY different from drums; therefore you need to also swap out the master cyl and the combo valve.

I suggest when you do that, you buy new (reman) calipers; install the "recall kit" in them; and do the combo valve mod. Then, make sure you use the parking brake EVERY SINGLE TIME you park the car, WITHOUT EXCEPTION, because that's how they stay adjusted. If you don't use the PB they will become less and less effective fairly quickly, leading to no rear brakes and a low mushy pedal.

 

Or you could find a rearend from a 89-92 rear disc car and swap that and master/combo.
I'm not a big fan of the mid 70s to late 80s rear disc setup. They just seem to be more trouble than they are worth. Some people have nooo problems with them at all tho..

 

Also, in fitting an 82-88 rear into an 92, you will probably experience difficulties with the parking brake and with the combination valve. The 82-88 parking brake has a tunnel-mounted adjuster that the 92 doesn't have. (I've read that some members have had to swap the earlier parking brake mechanism into their 90+ car.) The standard combination valve won't fit the tube nut threads of your 92. Those issues would be eliminated by doing the swap that TTOP suggests or by using Ed Miller's no hassle kit as well as a few other pieces.

http://www.flynbye.com/catalog/i30.html

http://www.flynbye.com/catalog/i160.html

http://www.flynbye.com/catalog/i199.html

JamesC

 

I would just swap the entire rear end rather than just the axles, since they will have little to do with fitting the brakes on.

 

True. At any rate, an 88 with rear discs is probably a 9-bolt and the axles wouldn't fit the 92 10-bolt anyway.

JamesC

 

JamesC, I know you are a supporter of the 9 bolt with the iron calipers...did your car come with the rear discs or did you do the axle swap? I think I have everything to do the rear disc iron caliper swap, but opinion on here scares me. In your opinion is it worth it, or just stick with the reliable drum setup with dependable parking brakes. The car will never be driven too hard, but I like the look of 4 wheel discs!

 

Actually, I prefer the 10-bolt, all things considered.

My car was originally equipped with 10.5" rotors and the infamous iron Delco-Moraine calipers. I never experienced any issues with them whatsoever. I did swap to PBR's a few years ago and have been satisfied with their superior performance.

Our hobby is all about modification. As a consequence, I'd go for discs.

JamesC

 

Thanks for your reply. I value your input. I guess if they don't work out, can always go back!

 

When you go to rebuild the Delco Moraine Calipers, see if you can still get the recall kit:

Part Number: 18019028 from GM Parts Direct, listed as "Actuator" and included parts for both rear calipers, pistons, springs, seals, etc.

It includes all of the rebuild parts and corrects some of the defects.

 

If you go the above route, the link below should be helpful:

http://members.shaw.ca/crussel/recalls/86c28/86c28.html

JamesC