First I made me a new tool that I have been wanting for a while, a case spreader. No more beating shims in. Now I just spread the case and lightly peck them in and realese the spreader. No more fighting to get the carrier out either. I set it up with a Ratech full install kit with wheel bearings. A Ratech spacer, no crush sleeve, and a Motive performance 3.89 ring and pinion. This was probablly the smoothest one of these has ever went for me. I started with the factory pinion shim, .027, and the pattern showed the pinion was a little too far out. So I add .002 to get .029" pinion shim. and the patern looked really good. So, just to see how close I was I stuck in my high dollar pinion depth checking tool. After some calculation the tool said the pinion depth should be 2.297". So I shined a light in the case to read the depth etched on top the pinion, guess what it read..........2.297 My buddy that I am building this for was sitting there and said, " I can not believe I just witnessed that, you got it down to thousandth just by looking at the pattern". I was like, yeah I am just that good....LOL. Only had to make one shim change, and we only had to knock the pinion out twice to get the preload right on the pinion.

Home made case spreader, I ended up using the gasket as a template and drilled holes to bolt it to the cover flange. Worked great. I was amazed at how little force it took to spread the case up to .010". I can really see where a good sturdy rear cover would help beef up the 10 bolt.



This rear is out of a 96 SS, with a factory AAM aluminum rear diff cover. This thing only had 60K miles on it and was covering the bottom of the car with oil from the pinion seal. The car is a M6, and it showed. I could move the yoke in and out, up and down by hand. The pinion bearings had all kinds of play. The only thing I can think happened is some one tryed to change the seal, the wrong way, or the crush sleeve collapsed from the shock of the 6 speed, from dumping the clutch.



Spreading the case, and checking how much it is spreading.



Checking pinion depth, without the case spread.



Final pattern









This rear is going behind a 500 hp 383 LT1, just hope it lives.

 

it will for a little while

but hey I got a 2001 4 channel 10 bolt for sale if your interested and want a back up

 

send me a PM if interested

 

Why didn't you use the holes in the case designed for the case spreader? Your tool in the first pic was set up for it.

 

Well, my bars were too wide and would not allow me to get the carrier in and out. If you notice how close the edges of the bars are to the edge of the opening. I would have had to grind a 1/4 inch off the bars to get the carrier in. I like doing it this way because it kept the tool tight against the flange as well.

 

I like the homemade case spreader,think I'll fab one up.
Never considered using the cover holes.

 

This may be splitting hairs but I would consider making it double adjustable if you are going to bolt it to the case in 4 places to avoid spreading the saddles on a angle.

 

I thought about that, but I dont think that it was hurting anything. I spread it out to .010 and released, it sprung back to zero everytime.

 

Update on how it's doing?

 

Waiting on a Racetronics fuel pump to go in while the rear is out. He is also going to clean it up and paint it.

 

Good job where you located? You can do mine when the time comes

 

This rear is back in the car and is for the most part silent. Has a slight decel whine but you have to really listen for it. I am pretty happy with it.

 

Nice! Mine (richmond 4.10s) is silent on decel but whines under acceleration. It's the worst between 40 and 55 then quiets down.

 

1.5s on stock rear end auto car

 

^ Jealous. I'm still a manual for now but we'll see how my beefed up rear takes some not-too-hard launches on 275/60 15 nitto radials in March...