Polaris Sportsman Diff pinion cover December 20, 2015 Ive seen some post on these and how they are an issue and that you should replace them with billet ones. I just don’t know much about them and what they do and if they are a problem in the 550’s. Can someone explain what they are etc. Thanks. Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related