I have Vault hubs and have a very small (couple of drops) leak on the black cap of the outer assembly. The hubs were serviced less than two years ago. Has anyone done the o-ring replacement on these and if so, how difficult is it? Can't find anything on YouTube or the web.

I've taken mine down and completely rebuilt mine twice in 8 years. It's not difficult at all. I bought all of the parts and hybrid grease from Eastern marine and trailer Parts Super Store. It's recommended to replace outer assembly and not re-use. Once you knock them out they never fit perfect again. If you PM your phone number i can take a screen shot of my receipt with all of the part numbers and text it to you. Or better yet send me your email and i can scan it and send it to you.