You haven't had a chance to anwer yet, and here lots of much the same advice up against each other. The common causes for vibration in these models are; worn motor belt, there is a timing belt inside that needs to be checked too, but it usually doesn't cause much vibration. As mentioned by several now, the machine has to be stable in the cabinet, as well as the cabinet feet on the floor. This adds can add up to quite a bit of rattle if more than one thing needs attention. When it's all checked, run the machine slowly with all plates off and see if you can detect any problem, something too loose, unhinged or comming appart. Even sticky parts can cause noise and vibrations, on some models parts move in open cam like links, and they can be a rattle if not all part move smoothly.