Here with the hub removed you can clearly see the groove worn in the seal surface of the axel housing by the rotating hub seal. This one has over 1/4 million miles on it, so yours may not be this bad. If you can catch your finger nail in the groove, it's time for a repair to prevent the new seal from leaking. And for the repair? That's what we're here for, so continue on.

At 10:16 PM 1/6/2007 -0500, Charles Jackson wrote:
"While I was replacing the rear oil seals I managed to bugger up the threads on the left side axel shaft carrier. After almost an hour with a file trying to clear the threads, I gave up. My supply of tools does not contain a properly sized die to allow me to chase the thread, of course.

I took a used nut I had on hand and sawed through one of the flats. With a flat tip screwdriver I spread the nut so I could position it on the inside threads, then I clamped the nut together, making certain the threads lined up properly. I then carefully unscrewed the nut using several back-and-forward motions, thereby re-cutting the threads on the axel."