Loud Grinding noise in Dryer

Question

My GE Dryer DSXH47EGOWW started making a horrible squeaking noise so my hubby sprayed the wheels inside with WD-40 - bad idea now it smells. While doing this he noticed a s***w missing on the inside of the dryer on the back. He put in a similar one and then when turned it on it started scraping noise back there even after he took it out with the small back panel off there are sparks coming out. It sound like the heating coil scraping or maybe something back there, but I cant figure out how to take it off to get to it. I got the top off but that doesn't seem to help me any. I can't tell if the first squeal stopped because I am afraid it will catch on fire if I run it. We have had this dryer for about 2 years... HELP!