i have recently (for that last week or 2) been experiencing that with mine & today the belt broke... i have read on here today that banging could be because the drum belt has moved.
tracie
October 2009
The drum is mounted on felt bearings just inside the door opening. If these have failed, the drum tends to rattle around.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix tumble dryers.