I need to replace the left rear axle on my 89 Iroc and was wondering if there were any brands out there to stay away from??

 

After market axles, such as Moser and Superior are good (I'm running Moser 26-spline). According to big gear head, beware of Alloy USA axles. Apparently the C-clip button isn't cut correctly, which causes problems with C-clip and cross-shaft installation. Should you be unfamiliar with the process of swapping out an axle, the following may be helpful:

https://www.thirdgen.org/forums/tran...ing-axles.html

JamesC

 

Thanks James. I am familliar with how to change everything, I've just been away from a third gen for quite some time and I am not up to par with good vs. Bad. There are sooo many new goodies out there now!

Now, If I can just get that 8mm bolt that someome rounded off out of the carrier pin I will be on my way.

 

Under an IROC, I wouldn't be surprised if you had a 9-bolt, not a 10-bolt.

 

If you have a 9 bolt, finding a replacement half shaft may be difficult. If you have a 10 bolt, the 89 should still be 26 spline. Third gen axles are the same length on both sides so all you need to do is find a donor car and pull an axle from either side.

If your 89 is a late in the production year model with a 10 bolt, it may have 28 spline axles. Those can only be found in 90-92 third gens. No other car has axles the same length as a third gen.

Aftermarket choices are plentiful. Moser is probably the best to buy. I have Moser in my 9" right now and have also had Strange axles. I like the Moser better. I bought 28 spline axles for a 10 bolt from tomsdifferentials.com many years ago for $125 each. I changed the carrier to 28 spline to use the larger axles.

 

Well it's deffinately a 10 bolt but out of what I still dont know? It does have a 3.23 gear but with an open diff. The prior owner changed the rear assembly and put a drum brake rear end in its place, Then he tried to perform a disc swap which I spent the better part of this day correcting so that the brakes would line up only to find a bent left axle and a rounded off carrier pin bolt. I am gonna try somthing different tomorow with the bolt. With any luck I can figure out what splines I have and go from there.
Hypathetical Q - Say this rear end came from a 91 RS with a V6, Would it geneally have 28 spline axles or does that have anything to do with year model VS engine?

 

If it's from a 91, it should have 28 splines but parts can be mixed and matched. There's nothing stopping someone with a 90-92 third gen from replacing a broken/belt axle with 26 spline components. There is no such thing as a V6/V8 diff. All the parts are the same. The only differences are if it came with a posi, govlock or open carrier and the gear ratio. The V8 cars should have come with at least an 8.5" diff but GM didn't think that way.

The carrier pin can be removed a number of ways. There's no torque on the threads, just under the head of the bolt. You could cut the head off then use a dental pick to unthread the bolt although this is difficult to do.

Weld a small nut on the head of the bolt. You only need it to crack the torque. Once the bolt comes out, the welded nut will probably prevent it from coming right out. Cut the nut off or cut the bolt and remove the rest of the pin.

Hammer and chisel to try and get it to turn.

On the front of the passenger tube close to the center section is an axle code. It's always difficult to find and read. The axle code can give you an idea on the year and what should have been in the diff from the factory.

 

No problems with my Superior Axles, they've been in and out (adjusting the gears) too many times to count.

 

OK, I got the bolt out and see that I have 26 spline axles. I think I am gonna try to find a rear axle assembly That way I can have a Housing for beefing up in the future and spare parts. I should be able to use an axle out of any 3rd gen 26 spline rear From 82-92 Regaurdles if It came with disc or drum?? Correct??

 

82-89 as long as it's a 10 bolt. 90-92, providing you can even find one, will be 28 spline.

Disk/drum shouldn't make a difference but the hub pilot may be slightly different. Nothing a die grinder couldn't fix.