sounds like you need to do a teardown and look for shiney areas. I recently had problems with lt & rt hubs (sfa) and it turned out to be the inner hub seal. there is a round spring in the seals which causes the seal to squeeze around the spindle. well the spring somehow came out and was grinding between the hub, bearing and spindle. try grabbing the top of your tire and push it in and pull it toward you. mine you could feel the play. after the new seals, it was sweet. just my 2cents.