I still have my original axels from my car. I replaced both at about 140k miles (boots torn). At the time it was just easier and faster to just install replacements. What I did in my spare time was order new boot kits from RA (came with boots, geese,clamps) and disassembled, cleaned and inspected all the balls and bearings and surfaces, and as it turns out there was very little wear on them, with new grease and boots they are still nice and tight/stiff. So now I have an extra set of spare axels should I ever need them.
It is not that hard to clean and re-grease/re/boot, just make sure to keep the parts together and make it hospital clean before it all goes back together. I think I used a HAYNES manual for reference and the disassemble and reassemble.
