very noise vibrating white knight dryer CL767?

My white Knight condenser dryer is that noisey that you carnt hear yourself speak i cleaned it all out and its been like that ever since, I have took the back off but i carnt remove the screws that are holding the drum, I think it could be the motor but carnt get at it, Also a little plastic comb like thing has fell off but i dont know were from hope you can help