Now if you are asking about the tool I would take it someplace and get it changed. There is a crush sleave behind the seal and bearing that perloads the bearings. If you do not know what you are doing and just slam the seal and yoke and nut back on you prob are not going to get it set correct. If the nut is too loose its going to mess the grear mesh up.. to tight and burn up the bearings. You have to set it bacj up just right.
I have done about a dozen this way:
Mark the nut with a scribe, prick punch, dremel tool, etc.
Mark the end of the pinion in line with the mark on the nut.
Remove nut, yoke, seal.
Clean nut and pinion thread with brake clean, carb cleaner, etc.
Install new seal and yoke.
Put thread locker on pinion thread.
Install nut and tighten to exact same spot using marks.
So far I have never had a recall. I know you shouldn't reuse the nut, but sometimes ya gotta do what ya gotta do.
I always scotch brite the yoke sealing surface incase the lip isn't riding in the same spot. And put a little lube on there too.