I know exactly what you are talking about! About 5 years ago I was running our F2 in wheat and I smelled something burning and got off to check and saw a fire between the grain bin and the engine! The straw from the beater had worked itself through the sagging sheet metal and touched the exhaust and walaa, instant fire! Talk about heart stopping! The only thing that saved it was a jug of Gatorade while I kept the machine running! From then on I have always carried a fire extinguisher on the combines. I didn't know if I was the only one with the sheet metal problem. None of our F's seem to have the problem (believe me, I checked!). What we did was just put the sheet metal back into place, drilled the holes bigger (in both the sheet metal and angle iron holding the sheet metal) and put in bolts with fender washers and make sure you use lock nuts. We didn't remove the walkers, although we had a small guy that fit in the inspection hole to start the nuts and bolts. Works like a charm! Good luck!