A quick question I have been running an RC10B5 Rear motor and I am seeing significantly more wear on the left had rear wheel bearing. This is the bearing that on the tire side of the rear hub. The bearing's dust cover was pretty much off and worn down to the metal. The bearing still works fine but I want to prevent it from damaging the new one. Any suggestions on cause and fix?

I should mention that where I drive is really dusty with unfortunately a lot of loose dirt. If that is what is causing the wear I would think it would happen on all the bearings but it was just this one.

It could have just been a defect in the bearing or maybe a piece of dirt got lodged in the seal at some point. I wouldn't worry too much unless it happens often. But one thing to check is if there is any slop in the driveline or the rear hubs. Vibrations can cause failures.

There is a little bit of side to side movement on the A Arm but all of them do it, seems off road cars have a bit more play in things than my Touring. I also wondered if the hex nut had some flash or other part of the plastic that was protruding and rubbing the bearing face. Is it worth it to check out the JConcepts or Associated aluminium hex nuts?

Yeah there should be a little play but nothing extreme. Definitely not as tight of tolerances as on road cars.

Absolutely going to the aluminum hexes would be preferable. There could be some flashing that got into the bearings, though unlikely. But aluminum hubs should help take out slop and prevent that possibility.

Thanks a bunch I'll check that out for sure. It is not a very expensive thing to upgrade and worth it if I don have to keep fussing around with this bearing.

Original B5 bearings were terrible from the factory. Replace them with rubber shielded bearings from Avid for $1 a piece and see if you still have an issue.