Originally Posted by Blakesrc

Been struggling with this myself for a the last few weeks(since I've built the truck) and just re did my rear diff last night again. mine feels fine when fresh for about 3 runs, then randomly locks up. From what I've read it appears to be the sun gear spacing. Last night I ended up with one side that is per instructions, a spacer between the cup and case and a spacer between the o-ring and sun gear. The other half has 2 spacers between the o-ring and sun gear. If i did it equally with the new shims per instructions, it would bind as soon as I bolted the diff assembly together. Seems to be a trial and error situation.

Blake