Interesting, I have never done the post attach top bolt check but will the next time I use it. I have never notice any in torque issues with the 3 bolts on the mount - they always remain at the torque setting. The allens are just the opposite. I do set them to 40 but it isn't uncommon for one to be off a bit after a day or 2 of towing.

The split allen occurred when using my AUH to tow a friend's new unit home. The initial setting to 40 just isn't comfortable feeling...