Can a 9 bolt from a 88 Iroc be rebuilt by just buying a new series 3 posi unit carrier and gears or do they take special parts? I couldn't really find anything from Summit that fits this year. Thanks

 

Yes it can be "rebuilt".

No the parts aren't "special", any more than any parts for any model of rear axle are. 9-bolts use 9-bolt parts, which, like every model of rear, are different from the equivalent parts in any other axle model though, if that's what you mean.

No I doubt Summit carries many parts for that rear. Usual source for parts for those these days is 9bolt.com which is in Australia. Pretty sure they can hook you up with a carrier. Maybe even a newer, worm-gear style one.

 

Hot damn Australia! It probs be cheaper to just find a 10 bolt on this side of the world and rebuild it wouldn't it??

 

Most likely.

 

The rear and its' successors were used more globally than N. America. Some reading (I would consider this.): https://www.thirdgen.org/forums/tran...rg-warner.html

 

Yes, the 9-bolt rear can be rebuilt. No, you can't get a new carrier from Summit, Jegs or anywhere else here in the states. All you can get around here are bearings, seals and 3.70:1 Motive ring and pinion gearset. 9-Bolt.com, out of Australia is a good vendor to get the other parts you can't get here. The original posi carrier is rebuildable with new friction cones and spider gears (available from 9-Bolt.com), or there are Torsen carrier options available from Australia. There are also a couple of things you can do to strengthen the 9-bolt (or a 10-bolt for that matter), such as a T/A Performance rear cover and pinion crush sleeve eliminator kit.

Overall cost will be a little higher for the 9-bolt parts compared to a GM 10-bolt, but you already have the 9-bolt. I would not go buy a 10-bolt and then rebuild it, that would negate the cost savings. If you were able to get a free 10-bolt, then it could make more sense.

The 9-bolt is a pretty good piece overall with a 4-pinion carrier, no c-clips to hold the axles in and inner bearing races for the axle bearings (instead of using the axle as the race).

 

There's a torson diff on ebay to replace the factory junk cone diff.

 

I have an 88 Iroc that had the 9-bolt that I bought in 1999 that I was building a 400sbc to put in it. I had a 2.77 gear and if I remember there were one or 2 choices of gear I could find. The problem for me was that you needed a different carrier for the 3.+ gears that were no place to be found, new or used. I really wanted to keep the 9 bolt but after searching for parts for months, I ended up buying a 91 Z28 10-bolt, which is a step up from the early 3rd generation 10-bolts. If I remember correctly, the gear diameter went from 7.5" 26 spline axles to a 7-5/8" 28 spline axles. This was back in early 2000's, so I don't know if things are different today. I think all of the 10-bolt housings are all the same 82-92, you just would just need to upgrade the 28 spline carrier, 7-5/8" gear and axles. Also I think you can use the 1993-2002 4th gen 10-bolt axles, but they are a little wider (same bolt pattern to the 82-92) and would probably need different offset wheels. Most of this info I just told you I think I got off of this forum back then.

I happen to have the original OEM Posi carrier from the 91 z28 (had ~38k miles on it) that I replaced with a SLP Torsen take-off carrier. I also have a brand set off Superior Evolution heavy duty axles, P/N EV10-4 and a new never use Superior 3.42 gear. All this will be for sale soon in the classifieds. If you wonder why I have this stuff, you can read about my 88 IrocZ that's been sitting for 20 years. https://www.thirdgen.org/forums/hist...ml#post6548882 I also have pictures of this stuff if you were interested in going this route. I just remembered I also an Aluminum heavy duty differential cover I am removing that I am going to sell also.

 

https://www.thirdgen.org/forums/tran...rg-warner.html

That thread shows how to put a torsen in a 9 bolt housing with part numbers. I just completed this myself with a 3.7 ratio and am looking forward to putting the rear end in the car this spring.