I have a 212 with manual PTO and hydraulic lift...in case any of that matters for the problem I'm having. The belt that runs from the pulley on the rear end the the variable speed pulley keeps slipping off the rear end. I have replaced the pulley itself (the lip had a subtle bend on one spot), the tension pulley spring and the belt and the belt still won't stay on. I have no idea what else to look at. It is coming off the rear end pulley, not the one on the variable speed side of things. When the belt slipped off the first time, there was no catastrophic event or anything...just a little bit of vibration for a second, then a thunk where the belt slipped off. When I put everything back together it will run for maybe 50ft and then the same thing happens. What else is back there that could be causing this?