Can anyone tell me the size of the butterfly screw/bolt that holds the rock/stone guard up. I am missing one in the left side of the trailer. I have tried testing various ones and can't seem to find the right size. I measured with a caliper and found it to be about 5.5 mm, or 3/16" in diameter but don't know if it's fine thread or course, or somewhere in between.
I can't access the other one to check it as it will only screw out enough to let the arm slide up and down. Help!