[A/S] Re: Hensley Hitch Install

["Maurice Riggins" <maurice.riggins@xxxxxxxxxxxxxxxx>]

Tom,
The first thing you need to keep in mind is that there is forward 
motion of the rig when all of this is happening.  But let me give you 
a static example of how the Hensley works.

Lets assume we have a some jacks that can lift either the trailer or 
the truck off their wheels and roll them sideways, as into a parallel 
parking spot.  If I put these jacks under the trailer and lift it off 
its wheels, when the trailer is hooked to a truck with a Hensley, you 
can push on either side of the trailer and it will not swing about 
the hitch point.  It will stay directly in line with the truck, and 
the truck will stay in its original orientation, as it would rolling 
down the road with all four tires having traction.  The trailer 
is "locked" to the truck because it's on the wide end of the 
trapezoid.

The only way to swing the truck with the trailer is if you lift the 
front or rear of the truck and reduce the rig to one pivot point and 
the truck and trailer WILL stay in a straight line.

Now, if we have the trailer tires on the ground and lift the truck 
with our sideways rolling jacks, the truck will easily push back and 
forth swinging about the hitch.  The truck is NOT "locked" to the 
trailer in the first place because it's on the narrow end of the 
trapezoid, so there's no "unlock" necessary.  The driver can steer 
the truck in either direction and cause the hitch to pivot one way or 
the other.

The very fact that the trailer can't sway means that it will not have 
the momentum to break the traction of the rear truck tires unless 
you're in a curve.  Even if it does, the rig is continuing to roll 
forward, and the driver can steer the truck in any direction because 
it ISN'T locked to the trailer like it ISN'T with a LOOSENED friction 
sway control... which can't stop the sway to prevent the jack knife 
in the first place because it has no anti-sway property when 
loosened.  And with friction sway controls in the rain, you don't 
have to loosen them... they lose friction anyway.

Probably the worst thing that could happen in a jack knife situation 
is that the trailer tires regain traction.  The trailer IS going to 
roll in the direction of the jack knife and it's going to roll hard.  
That's why it's critical to not let sway get you into a jack knife 
situation in the first place.  And one more time... a loosened 
friction sway control isn't going to do that.

Hope this helps,
--
Maurice
WBCCI 5446