I have a couple of questions about the pins where the boom hydraulic ram meets the boom. Mine has had a hard life and the pins have worn out the hole in the boom. The previous owner has welded a new plate on both sides over the top of the elongated hole and put a new longer pin in. It all looks a bit untidy so I want to fix it up and get it back to its correct way. I think the problem was they never greased the pins via the nipple in the ram so the pin was turning in the boom instead. My questions are: Can you replace the sleeves in the ram? - The parts list shows replaceable pins for the bottom pivot of that ram but not the upper pivot. Also, does the upper pin have any means of being secured to the boom so that it can only rotate in the end of the ram and not in the hole in the boom?