Well. J-J you made a very good point there about the instructions. I just tried to contact the manufacturer to get the installation instructions. It turns out this particular hitch have not been made for 6 years and they DO NOT

have the instructions anymore



. The lady on the phone asked where and when I bought it. I said : a couple of days ago from a local retailer.
She guessed that it has been sitting in some warehouse for at least 6 years.
I will take some more pictures over the weekend and ask what you guys think of my intended installation process (ie: where I want to weld)
As for how it works. The large round pin has to be rotated so the flat side faces the towing ball. Then when the coupler is lowered onto the ball I let go of the little lever and a spring returns the pin to the lock position when the flat side faces away from the ball. On the other side the hole is for the safety pin that prevents the large pin from rotating. I see no option to adjust it.
Edit: The more I think about it the more I lean toward returning the coupler.