chracatoa wrote:
Ron,
How about the sway bars (sometimes integrated on the WD system). Wouldn't those cause lateral forces as well for regular hitches?
Sure they would BUT the trailer will eventually win out, overcome that friction control, and sway anyway. Since the Hensley and PP hitches do not allow movement at the ball iniated by the trailer, all the forces are transmitted through the receiver to the tow vehicle. The hitches themselves do not cause the yaw forces, the trailer does. They just transfer it into the tow vehicle through the receiver.
In the case of the Hensley and PP hitches, instead of the trailer winning, the yaw forces are projected forward to near the rear axle so that the movement is not felt very much by the driver and does not result in much, if any, steering correction. Those forces are still there however and must be overcome by the friction of the tires on the pavement. If the receiver cannot stand the forces, then it will twist and crack or break off. This has happened to more than one member of this forum. This is one reason that I have upgraded my receiver to a much heavier one than came stock on my vehicle.
Barney