the washer in the spin cycles violently shake. Ive checked the balance and have re-arranged clothes in tub several times only to get same results. it also doesnt matter what size the load is.
Take a look at the video library in the Sticky at the top of the washer forum page and you will find one that shows you how to take off the cabinet.
Check the support structure for breaks, maybe hairline cracks, check the springs and the pads. If you cannot find a problem try replacing the springs, they can go bad without the damage being visible.