I don't think the jaws are going to snap shut on that head. You made need the pressure of the truck backing into them to close the jaws. I've had a circumstance where I couldn't get the lever in the locked position so I backed the truck a little harder into the trailer which closed the jaws all the way and was then easy to put in the "lock" position. I have always had the feeling that pulling the lever full back was only serving to lock the jaws not contributing to closing the jaws like some other hitches. Might be wrong here.
