Hi Junkman .Have you checked out the grain pan to see if its clean (up front under the concave) If moisture has got in and crud builds up there then it puts all of the shaker assembly out of balance (extra mass to move) and you will have all sorts of trouble , broken pitmans, shot bearings, stress fractures in the tinwork and even in the frame around the crank bearings. That serrated shaker pan needs to be smooth and shiny clean, if it aint you will have trouble.Have fun greyhawk