Been restoring my 1998 Honda fourtrax 300fw I picked up last summer on the cheap with a mud filled rear diff and bum brakes. The pinion bearing removal in these are a pain. It’s 50/50 % chance of getting it out IMO without damming the case housing. Luckily you can buy aftermarket case housings for about $150+- if you do. I needed a new pinion bearing retaining clip so I went ahead and ordered the bearing/clip OEM from Honda. Hopefully it will last another good while as the the factory one did. Mine was corrosion and mud/dirt stained so a lot of clean up was required. I reused my factory ring and pinion gears so I was able to reuse the old shims. Pay attention to how they come out, especially on the ring gear. It’s hard to pick up .005mm thickness difference with the naked eye! When installed correctly by “feel”, you will have LESS gear backlash when configured correctly. And I my case was very little so pay attention. Anyway, a lot of long nights cleaning, I was able to get my rear diff rebuilt. I reused all the old hardware except the drain bolt, which I always try to keep fresh on anything I do, for ease and less trouble I the future. A wire wheel on a bench grinder will go along ways. The old rusty hardware cleaned up nice, and ran a thread die to clean up any bad threads. I’ll show a few pics of before and after. I found a beautiful color that I liked that added a nice clean and custom look to my diff. If I can help anyone tackling this project please feel free to drop questions, comments, and criticism below. I’ll help anyway I can.