I found out that my stock 87 rear end had the same problem as everyone else's. The cones are shot and I figured instead of buying another cone style carrier, I would do some upgrading.

I bought a 95 Z28 rear diff for a good price. I was told that it has an Eaton 28 Spline posi unit in there. I wanted to swap the carriers until I found out that my axles were 26 spline. I would like to keep my rims so, I am going to use the Eaton carrier and just get new 28 spline axles. I have searched the Jegs and Summit site and have found a few variations. The current number I found is 718-A102804

http://www.jegs.com/webapp/wcs/store...0002_396626_-1

or

http://store.summitracing.com/partde...5&autoview=sku

Will these work for my car or what would you recommend?

I still have to change my ratio's to 3:73 too.

 

1. Is your existing rear a 9-bolt or a 10-bolt?

2. If it's a 10-bolt, it very likely doesn't have a posi at all. Which would explain why it doesn't seem to be doing anything.

3. What does it look like inside? Changed the fluid lately?

4. If you have a 10-bolt with 26-spline axles, get rid of them, and upgrade to 28. Odds are they need replacing anyway, they about always do. What do the bearing surfaces look like? When you're changing the fluid, look at them. DO NOT spend giga$$$ to buy a 26-spline carrier, ESPECIALLY not if your axles are less than perfect. That's just plain economic suicide. Next thing you know, you'll be buying axles ANYWAY, and you'll be stuck buying 26-spline crap to fit your giga$$$ carrier. You'll feel stupid then, maybe even almost as stupid as me.

5. You'll probably find that it's cheaper to just buy a whole LS1 rear, than to futz around with "upgrading" your old junk. Take your time and find one with the gear you want already in it. There's plenty of em out there.

 

My existing rear is a 10 bolt 26 spine. The main problem started after a women's hair net got caught up right rear axle seal and it dumped all the diff fluid. I have completely gutted the 87 diff and am going to put new seals, bearings in. I already have the eaton posi carrier that is clutch style and not a cone carrier. I have to ensure it is a 28 spline though. I was just going to pull the carrier assembly out of the 95 diff 10 bolt and put it in the 87 diff 10 bolt. I just have to find out what the actually size of the axles are.. I do plan on running on mosers. See above thread for the 2 links that I have enclosed to see if these are the right ones to order before I make another mistake.

 

I'm acquainted with Moser axles. No need to look at the links.

I'd suggest these instead. http://store.summitracing.com/partde...SAG%2DEV10%2D4 They're better axles, with rolled splines and heat-treated AFTER splining rather than metal left sufficiently soft in the heat-treating BEFORE spliningto allow cut splines on them. Basically, you don't have a situation that requires "custom" axles; best to use production axles, and leave the "custom" ones only for situations where production-line ones aren't available.

A 95 car would have had an Auburn :barf: carrier from the factory, unless of course, someone had changed it out. If what you have looks like these, then it's an Auburn.



If it has the 2 little weights on little shafts, like this one, then it's not a posi at all, it's an Eaton Gov-Lock.



If so, don't drive it on pavement.

The Superior axles come with bearings and seals, BTW.

If the rear ran dry, then the pinion bearings are shot, and the gears are probably damaged as well. I still think you're throwing good money after bad.

 

I kind of understand by not running on pavement as I will be tearing up tires when cornering or breaking things. RIGHT?? I emailed the guy that I bought the rear end diff from. I am requesting more information on the Eaton system.. He told me that the clutches were rebuilt not too long ago. I still have the diff sitting on the floor in the garage under the car ready to tear into it. My original diff has already every bearing and seal pulled on it and I checked the bearings and there were 3 that were bluish colored or wore out so I know that I burned them. I also pulled all the races out and found 2 that were scored pretty bad. Common sense also tells anyone who is changing the bearing to check the races and replace as needed. I know if you buy timken you get both most of the time.
That was one of my major questions that I had.. I measured the axles in the garage and they were just over 30 inches long. I didn't know what other people used or liked. I will start hopefully tonight to tear the diff apart and left you know what I find.

You always find a plethura of knowledge from people if you ask the right question! I appreciate the help!

 

One guy on here had one of those Grenade-Locks, that when it did what they always do (grenaded), it sent the shrapnel NOT ONLY through the rear end cover, BUT ALSO all the way into the gas tank. Hopefully that's not what you're dealing with. They are GARBAGE, not suitable for high-performance use, built for low-speed low-power use with small motors and granny gears on traction-limited surfaces such as mud at low speeds.

The Eaton "hi-perf" differentials are another matter entirely. Those are probably the best clutch-type unit you can get for these rears. THey're also about $500 new. Like this one here. http://store.summitracing.com/partde...%2D19599%2D010

The axles for these cars are about 30¼" long, so your measurement is about right.