I have a old hd 4x4 6.2 chevy that was leaking oil out of the rear axle seals(140,000),i did not want to deal with it,so i heated up a large tube of moly grease.on a stove and injected it into the differential.A 100,000 miles later it still did not leak, but i wanted to check it out.The oil came out very thick and i think the moly seperated and ended up being a layer of sediment.When i went to install new bearings and seals i compared the new bearings with the old ones with some calipers,and could find no difference.So i put the old american bearings back in.Why take a chance with unproven new bearings made in another country.All my differentials and geared trans have heavier oil then stock.I believe in film strength.