I have a Gibson Heavy Duty Automatic electric clothes dryer (Model DE27A7WXFE) which was built in November of 1992. It has developed a terrible screeching sound when clothes are being dried. Sometimes it disappears after running for a while - sometimes not. I am thinking it could possibly be a drum support bearing? The belt appears OK but should probably be replaced as well. Is there anything else that should be replaced while doing this fix? Is it an easy fix? Help! Thanks...