I had a leak in the rear drums of my 88 4wd.I read a few articles on the internet and checked my differential vent and it was frozen and the rear end was under pressure.I heard that when this happens it rinses the grease out of the bearings.Does anyone know anything about this?What kind of grease is recommended to regrease the bearings? how is it applied?

 

The bearings are not grease-able. You will need to replace them along with the seals, bearing retainers and brake shoes to do it properly. It requires a press and an adapter for the axle. Or you can replace just the seals and brakes and hope for the best. I've done it before and drove another 20k before the bearings started to make noise