Open front panel and make sure the 6 springs are all intact. Also the Halo Skid Plate at bottom of tub frame may be worn and needs to be replaced. Do some inspecting 1st. Run the washer with the front panel off to see whats going on. Is the violent shaking coming from the tub or the frame. It could shake violently from an off center or unbalanced load also I just went on a service call where the rubber feet on the bottom were missing the feet were off balance and the machine would walk across the floor! Had to install the missing rubber feet and re-balance all 4 feet! Let us know what you find - You should have 4 rubber pads under the feet of the machine.