If you look for my original post it will show what I did for a rebuild. I used Timken bearings and races for my rebuild. I recommend Lucas oil stabilizer for the box. You can run it at 100% but I thin it a little with 140W Lucas synthetic gear oil, 10%. After you install new bearings change out the oil in 1500 miles and check pinion preload without the seal installed. You want no less than 180 inch pounds with new bearings. If you backlash is no good you have to fabricate your own pinion shims.