This furnace was squealing loud metal on metal. The blower wheel was loose on the motor shaft. It slid down ans touch the side of the housing. It was turned off before any motor damage. We used a flywheel puller to get it back in position. The wheel and motor work fine for now. This is a 20 year old furnace. A motor and blower wheel replacement would be to expensive. It would have been time to replace it. Aaac service fixed it for under $120. Not all motors make it they usually burn out from the stress caused by the metal scrapping.. Aaac service heating and cooling in Mcdonough area 7708754113 and Aaac service in Fayetteville area 4049524510.