Re: [A/S] Suburban/"Lockup"

["James Clark" <jec1938@xxxxxxxxxxxx>]

What I am calling "lockup" is the Hensley method of preventing the
trailer from wagging the truck... The linkage from the trailer to the
truck is wider at the trailer end and narrower at the truck end... ie
the distance between the joints at the end of the links is the secret
to why the truck can easily turn and the trailer can not... (locked up
due to the link geometry) If you have seen the demo Hensley takes to
their gatherings, you have seen the attempts to swing the demo from
the trailer end fail while the truck end can easily turn the demo
platform...(I recommend attending some or all of the Hensley get
togethers.. there is more to be learned than first meets the eye) 

Another little "secret" is the amount of damage you can cause if the
chains are too short, or are connected without crossing the chains
(left side trailer to right side truck) I suspect this to be the cause
 of the failure of Patti's hitch... Her sharp turn may have caused a
short or uncrossed chain to bind the hitch and something has to give
because the head can no longer turn/fold...Either the stiffener bar
folds up or the receiver head twists ....In my case it was uncrossed
chains do to too many people trying to help hook up and the stiffener
bar folded like a paper clip at the first turn, accompanied by a large
bang..... At this point the hitch has no way to keep the trailer part
of the hitch straight with the trailer and the whole assembly flops
around... very interesting driving.. lots of sway...( the bolts in the
trailer frame brackets may fail/shear and relieve the stress without
bending bars, but not always..and something has to give..)

If you have had problems with bending stiffener bars, you are no doube
aware that the bars push against the head and the ears on the head are
more cosmetic than functional...The original hitch had a slot that the
pin pushed against....

I am going on 5 or so years with the Hensley and have a few
suggestions for the new or still learning user...

1. Never fail to cross the chains...

2. Don't park with the hitch in a low spot like a ditch with the truck
angled up and the rear of the trailer high... you may never get
hitched up again...

3..Use the crank up bar adjusters to level the head when hooking
up..The head needs to be fairly straight with the oncoming bar or the
hookup will jam and you will be sliding the trailer around...

4. Purchase one of the side to side screw adjusters for the jack
stand..being able to move the front of the trailer an inch or so may
save you a half hour of driving back and forth..

5.  Don't worry too much if you lose the square wrench that comes with
the Hensley, a good kick will seat the "over center arm" and any bar
or tire wrench with the "screw driver tip" will pop it open...

6.  Never.. Never partially do something involved with the hook up.. 
don't insert the bar in the receiver without putting the pin and the
safety in place.. Don't crank up some of the stabalizers and go to
something else.. crank them all up or you will be cutting divots with
the last one until it folds up...Don't snap the "over center arms" in
place without putting the safety pins in place... 

7. Carry some spares... an extra receiver pin and safety.. the Hensley
kit..They seldom break, but now and then they learn to walk at the
most inopportune time... 

8.  Have a list for the final walk around... after a while you will
mamorize it, but if you have trouble with concentration, you might
miss an item... (like the sign at an RV park.. ?? antenna down, door
step up, wife in the truck??? )

There are probably more good tips out there, but this is getting way
too long... 

Jim Clark