When my Duet Sport goes into Spin, it sounds like a freight train, and it takes forever to balance when trying to spin. What could the problem be?
Take off the back and and top and see if a support strut is broken. If they are ok a problem with the tub bearing may be the cause, in which case you will want to consider a new machine.
Bearings fail in front loader in part because of not using HE detergent and putting in too much.