Originally Posted by JStanley
Or just go out now and then to check that the nut is tight enough.
Good advice. I noticed ours was loose last summer when I was unhitching and saw it rotate a bit. I took it to a hitch shop, and they retightened it for me at no charge.
FYI, the Reese documents mention the lock washer on the ball, but not where it should go in the system. I'm pretty sure my lock washer is next to the nut.