Its your inner tub bearing that is causing the problem,it is going bad and will continue to do so. You have to buy the whole inner tub in order to get a new bearing or you could have someone press it out and find the part number to replace it with.
Kenmore Front Loader- Hard Thumping Noise In Spin Cycle And The Front Of The Inner Tub Is Touching The Outer Tub, I Can Hear And Feel It When I Spin The Tub By Hand, Is There A Fix For This?