Why is my washer vibrating or shaking excessively during a cycle?

Excessive vibration or shaking is commonly caused by the washer not being level, the feet not being in firm contact with the floor, or an unbalanced or twisted load. Make sure all front and rear feet are in firm contact with the floor and the washer is level. Load dry items in loose heaps evenly around the basket wall and avoid washing single items or tightly packed loads. (Page 7)