If the machine is grinding when the drum turns, then either there is something caught between the inner and outer drums or it's time for either new bearings or a new machine. An intact belt that has come off the drum is usually a sign of worn bearings that have made the pulley wheel wobble. However, sometimes if the machine has been working too hard with heavy loads , the pulley wheel can work loose off the shaft and shedd the intact belt.
Check your machine's warranty first before anything else, and try a little detective work to eliminate the noise.
Maximo, July 2008