have a Raptor model 9392215 serial number 18117238. the transmission belt jumps off pulley reinstalled belt two times and each time went to move belt jumped off pulleys, installed new belt when to test belt jumped off pulley. so was thinking might be small pulley replaced it reinstalled belt, went to test the belt broke. looked at transmission mounts all look good. thus looking for any clues as to what could be the cause. thanks