Used the online chat feature to diagnose the likely cause and identify part which was a gear case. Order arrived in two days even with standard shipping. AppliancePartsPros.com did not have a repair video but found some on the internet. Completed repair in about two hours; gear case replacement requires removing the inner tub, laying machine on its side and removing every drive system component. New part was a perfect match. Reassembled the machine, recalibration sequence (also found online) and machine is working great.