Just thought I would offer a little info to those having problems with your axle seals leaking because the surface on your axles are rough or grooved out from the years of use. I just went through this after rebuilding my entire Bronco. Drove it a bit and the right real axle seal was leaking. It had all new parts in it as I rebuilt the complete rear end including clutches and gears with all new seals and bearings. Pulled it apart and the seal was riding on the old area that had been worn down a bit. I have a friend that has a hydraulic shop and asked him if he had a double lip seal. He didn't have one in stock but got his book and found one that was thinner and had a double lip seal. I set the seal in the same depth as the original thicker one and that allowed the seal lip to ride on the nice machined finish. The number/size of the seal is OS-1.37x2.37x0.31TB. It was a lot easier than installing a sleeve and was a pretty cheap fix. Hope this helps someone in the future. Ken