I would repace all of the seals and have look at the bearings for signs oof wear. When the seals wear out they let gear lube pass and it washes all the grease away. Although the bearings never really run dry, they are designed to be lubed by grease and I suspect this advances wear at a higher rate than would normally happen.
There has been some discussion lately about the right rear wheel bearing. I would not, under and circumstances, use a regular ball bearing as found on the left side of the axle. The right side uses a special low speed, high load,self aligning bearing of the barrel roller type. Some have suggested that you can use the twin row ball bearing type, which you can, but I advise against this. Yes, the original type bearing is a bit harder to find, and yes, it's considerably more exspensive, but this isn't a place to cut corners with the purpose navigating them.
