So I decided I wanted a little more performance, and towing prowess. I ordered some blue box Motive 4.30 gears, part number GM10-430 and a Ratech rebuild kit. I also ordered a Ratech solid pinion spacer. I decided a new cover would be nice also.
Motive gears and cover.
Opened it up and found an open differential. I wasn't too thrilled about this, I figured it had the g80 locking diff. Only thing I can figure is because it was full time awd they skipped the locking diff.
Found a buddy who had a g80 sitting in his garage across town. So I drove over and got it. Here I was passing The Strand Theatre, it is an old and decorative building. Apparently I was missing the concert.
Here's the g80 and the stock diff:
Basically there are two bearing sizes for these diffs. The problem is its not just the diffs that are different its the actual housing that's machined bigger. So the deal is you have a small bearing that mates with some diffs and housings, and a larger bearing that mates with other diffs and housings. You dont know what you have until you measure it. The s10 the g80 came out of has the small bearing, and my housing is machined for the larger bearing, and they dont make a bearing that will make it work. So, back to open diff I go. I set the gears up for those interested at 10 pinion preload with no seal, 20 with seal, and 30 with carrier and backlash was about 5/6. I used a 40 shim under the pinion bearing and the pattern was perfectly centered and egg shaped, no hard lines. I was very happy with how these gears went together. I did have to bend the stock panhard rod slightly to clear the cover since its larger then stock.
Driving impressions: light throttle acceleration is very easy, motor never works hard, the converter tightened up its manners and feels really close to stock at light throttle. Hwy cruise it accelerates easily without unlocking the converter. And the little bit Ive rolled into the throttle the rpms climb really quick. Cruise rpm is about 2500 @ 80, and climbs up pretty quick from there if you increase speed. The truck is on 31 inch tires.
