First Thing first, rplace ALL the bearings in that diff, and you front diff. Also if you have been running in water, check the wheel bearings for rust and stuff. Buy Blue Star Bearings or BOCA bearings<-THE BEST!!, but pricy, go for the Ultra seals. Second, check your spider gears. you will prolly need to check your ring gear for signs of improper mesh. When you put your diff back together, apply some JB weld around the cup edge to glue it to the ring gear, also screw it in.
I've been doing a lot of reading lately and I keep coming across Boca Bearrings. Seems as if a lot of the 'hardcore' racers and bashers are running them. I also hear a lot of good about bluestar. I'm going to order a couple of both and check them out.
Does anyone know if I can still pull the plates and clean and repack either set of these bearrings? Thats the most important feature to me.