What's wrong with washer when the basket bangs against the inside during spin cycle?

Wash load is off balance.What's wrong with washer when the basket bangs against the inside during spin cycle?
Too heavy a load moved to one side of the basket when washed. You would need to stop washer at that time and redistribute the washing to be even. If this happened previously without fixing, the basket may be out of alignment Might need a repairman to realign.What's wrong with washer when the basket bangs against the inside during spin cycle?
Maybe the load isn't evenly spread around - if it is too heavy on one side then it will make that noise. Just open it and push the stuff around so it is all even, then start it back up and see if it is quiet.
Could be a load off balance or a broken tub support spring. Depends on several things like brand of washer, age or is it a front load/ top load.
Basket (drum) bearings are shot. You'll need to remove the drum and replace the bearings, not a big deal