I got this old dryer and it works ok most of the time and then every now and then it will make this terrible terrible screeching noise. I think it is the belt or pulley but i am not sure how to tell which. 
I haven’t taken it apart except the top raised up. I can see the belt is in one piece and it looks like it isn’t staying where it is supposed to. Completely knew at trying to fix mush of anything just looking for some advice on where to start. or at least an idea of how to make it shut up! lol. Please help me out. 