I have a electric dryer that has been making a loud high pitch squeaking noise. Sometimes it does it and sometimes it doesn't. It has been more consistent lately that it is doing it more often. Well a couple days ago it started making a thumping sound like shoes are in the dryer. I can take everything out of the dryer and it still makes the sound. I took the top off and looked to see if anything was loose or hanging and nothing looked out of the ordinary. Not really sure what i was looking for just anything obvious. Don't really know how to take the back off. Any thoughts on what this could be and maybe a tech manual on how to take this thing apart?