wnjj wrote:
I’m curious how there could be enough friction to overcome a properly torqued ball shank nut. ...
A couple years ago, we were in South Carolina when I realized my hitch ball nut was loose. I have an Equal-i-zer WD system and I ended up taking the nut to several places to find a socket that would fit it.
We finally found a Mom-&-Pop auto parts store that had the right socket, and it was thin walled enough to insert the pocket under my hitch head (for those who have Equal-i-zer's, you know what I mean.
I ended up buy a new breaker bar with it, since it was a 3/4 inch socket shaft. I was beginning to get real concerned after going to the 3rd place and still couldn't find the socket to fit it. But persistance paid off.
I now keep that socket and that breaker bar in my RV specific tool box which stays in the back of the truck all the time. Every time I put the hitch in the receiver, I grab the socket and breaker and give it a little "umph".... which is always tight and I physically can't get it any tighter by hand without a cheater or something.
Well, after 2 more years, the nut has never wiggled loose again. I was extremely lucky to realize the problem when the ball wiggled after unhitching the trailer. Just a few more miles down the road, and the nut could have fallen off completely. Then, only the WD bars themselves would actually be causing enough force downward to hold the ball from coming out of the hole. Yea, it was a "reality check" moment for sure.
So yes, the nut can come loose on the hitch ball.