Thanks guys, we ended up finding the problem. We had broke one of the black plastic topped wingnuts that lock in the square frames. We took one from one of the hat drivers and didn't reallize it's a little longer than the ones that are on the back frame holder. When that 1 would get moved to hold in a square frame, it was just long enough to barely touch inside when the frame is moving back and forth and do a little grinding. I'm glad we found it before it went too long and dug in.