I have a 5 year old Frigidaire clothes drier. It started making terrible squealing noises recently, and since I don't run piglets in my dryer, I suspected something was wearing out. After some internet research, I learned it may be the rear main bearing, which is difficult to replace yourself.
We called an appliance repairman, and sure enough, $140 later, we had a new main bearing and a quiet dryer. So, if you have a squeaky Frigidaire dryer, it may be the rear main bearing. It will cost about $150 to fix.