Well it's been almost a year since I bought my 12,000 lb HF winch. Last weekend it left me dead in the woods with 50ft of line out. Long story short, I bent the spool so it basically locked up and couldn't rotate. Tore the whole damn thing apart to investigate. Some things I found after a year of use, probably at least used it a dozen times.
-brushes looked pretty good. There are 4 of them, spring loaded positioned 90-deg apart from each other around the rotor. Prob 8-10mm thick so it would take forever to wear them down!
-minor dirt/grime build up on the rotor. I used brake cleaner on these for a quick cleanup
-I was a little disappointed with the planetary gear setup. When I took this apart there was a lot of rusty water that pored out. The outer ring gear was already pitted with rust deposits. The grease that was in there felt like peanut butter although seemed to be doing its job. Must be cheap Chinese grease! I pumped it full of grease when I put back together. Also used rtv instead of the cheap/thin felt gasket matl.
-worst prob I found is I bent the spool. My guess is the bolts that hold the horizontal bars together loosened up and allowed the entire winch to twist.
I tried to straighten the spool with some hammer blows and bench vise but it still won't free spool when tightened back up. I found the parts list online, part #26 hub asm. Put a request in for parts quote. Might get a machine shop to chuck it up and see what they can do. Stay tuned.