The gas dryer drum does not tumble.I removed the top and the bulkhead of the dryer, the belt was not in place when I removed the appliance top. Once I got into it I found that the belt was broken and laying on the floor of the appliance. I replaced the defective belt and checked the drum wheels, idler pulley , glides and felt slides. Once the new belt was installed and the dryer was assembled, I verified my repair was solid and that the flame assembly still ignited and burnt properly. I did find condensation so I passed along to the customer that they should check the end of their dryer vent.