When I took my front loading washer apart, I noticed rubber debris all over everything. I then saw the belt was broken and wrapped around the pulley and spindle. I first just replaced the belt, not realizing the pulley was warped and severely worn where it goes on the spindle coming out of the drum. If the pulley does not fit tightly onto the spindle, then it will need to be replaced as well, or else the belt will come back off as it spins.
After replacing both pieces, the washer works normally again. A relatively simple fix, but I advise replacing both pieces at once to save you time.