Dave, that's a great idea. I'll have a better look at the thread in a couple of days. I probably won't get back to work on the truck until Tuesday.
If it doesn't clean up...I really like the stud idea. Max torque on those corner nuts is 15ftlbs...even if the threads are really bad a little red loctite on a stud might hold.
I'm still hoping it will clean up and a new bolt will do...but the stud idea is next if that doesn't work.
