Built another 10 bolt this weekend.
11-20-2011, 07:35 PM
#1
Built another 10 bolt this weekend. 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.
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.
Last edited by 96lt4c4; 11-20-2011 at 07:41 PM.
11-21-2011, 03:33 AM
#5
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.
