I think Hughes has some mods on their site & you might Google it. If you go to www.moparchat.com then scroll down to & click on "circle track chat" there is an oiling sticky at the top of the page: "Sanborns oiling mods". it is SB orientated but alot bleeds over. it'll take you several hours to absorb it all but it is worth it. this was my last one. (screen added later) EDIT & I reduced the protrusion