Our clothes dryer has been making screeching noises for some time. I have a feeling a bearing or maybe both of them are going out. The back of the dryer in a spot in the left upper part of the back gets really, really hot-burn you hot. Are they that complicated to replace or should I get a repairman in? I've taken it apart and used lock graphite to try to lubricate the bearing but it doesn't seem to be working. Any suggestions?