I had the same problem. Was shellling corn felt a slight vibration,nothing big.I found the problem,tore the side out aroung the bearing flanges. Had to weld a piece from a bean head over the hole. 2 days later I was cutting beans and felt the vibration right away,as it was on the fast side. Threw another hammer off.It had about 200 hours on it when it happened. It is also a 05 model. They are going to fix mine this winter,the whole side will have to be replaced.There is a problem with this chopper for sure. The hammers on mine break right across the hole. IG