Grinding and banging? The grinding noise is probably the drum has dropped and scraping on inside body of dryer. The banging is probably the drum spinning out of true.
Reason? Bearing in the back of drum is U/S you may find that the shaft that the bearing sits on is damaged or scored. Time for a new drier don't bother replacing bearing these usually last the life of the machine so when they go get a new drier. Sorry!!
carlito, February 2009
