Answer Hello Becky101. Check and see if the rollers are bad on the unit and the idler pulley. If the idler is bad, you will need to order and replace the idler assembly WP53-2287. Both of these can cause the belt to slip off the unit if the tub is jumping ot the pulley is bad. Also, a bad spot in the belt can cause the issue as well. Read More... Answered by AppliancePartsPros.com | Tuesday, June 12, 2012