If its that old have ever had it cleaned? Pull the front off and check the duct where the filter goes in. Clean that, and check for a clog in the exhaust goin out of your residence thru the flex duct or replace if it is old. It will blow a fuse in your dryer sooner or later if clogged and you will have no heat at all. I to have seen the broken blowers from the motor housing caused from getting brittle because of heat so do check that to while you have it apart.