With all the examples here of not being able to move in grass or backing a bumper tow up an incline I wonder how many drivers got out an unloaded their weight distribution bars. The WDH causes the front TV wheels to dig in plus the trailer tires while at the same time unloading the truck's rear traction tires. It is possible when backing up a hill to lift the driven wheels off the ground with a stiff hitch joint. I knew a guy who could spin his tires on dry pavement because his WDH was jacked up so much.