Does anyone know if you pack rear wheel bearings on a full floating axle on a silverado 2500 hd? I assume the diff fluid lubes the bearings good enough but i've heard others say that they pack them as well. Also, the dealer obviously recommends replacing the thin metal (.06" thick) gasket/oil seal behind the axle flange that seals the axle to the bearing hub but can some RTV be good enough to re-seal. Dealer and parts store want $30 each for them. Thanks.