The problem could be either one of many things. The belt is on its way out and should be checked for splits or cracks. The belt might be slipping on the motor spindle.
Another well known problem is the jockey wheel/s these keep a tension on the belt and one of these wheels could have a bush worn so that when the wheel is spun it makes a grating noise. The noise is most certainly due to one of these problems. The only other thing that could cause this is the bearing that supports the spindle on the drum thus allowing the drum to drop which will cause rubbing against the body of the drier hence the noise.
Carlito Corway, January 2008
