Hy Tomcoe, from how you describe it it sounds like you have the type of seal which seals around the end of the axle tube. This type of seal was used when you had grease packed bearings in the rear hub. As far as I know these seals are made of unobtainium, (they are no longer available). If you clean all of the grease out of your rear hubs you can lube the bearings with diff. oil, just eliminate the seals at the outboard end and replace that with a gasket between the axle and the hub. Make sure the diff. oil is up to the level of the fill plug on the cover at the rear of the diff. housing, if you jack up the rear of the truck first on one side and then the other, that will allow lube to run down the tubes into the hubs before you drive the truck, any excess oil will level out when the truck is back on the ground, hope that helps.
