Spin Problem?

I have a Kenmore 80 series washer. Recently I noticed no matter how large of a load I have in the washer during the spin cycle it vibrates like it is out of balance. I can put my hands on the top of the washer at the front and it stops but as soon as I remove my hands, the vibration starts again. The washer actually walks toward the wall while this is happening. What is the problem and how is it repaired?