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 Two
of the great mysteries for trailer enthusiasts, whether
they have towed for years or are just starting out, is how
their equalizing hitch works and how to adjust it properly.
I look at the set-up of every trailer I pass on the highway
and it is rare that I find one that is connected with everything
adjusted, as it should be. It is also not unusual to see
combinations that have an equalizing hitch just resting
on a ball.
Without an equalizing hitch we would not be able to tow
trailers of any substantial weight. A trailer needs hitch
weight to be stable and it is the action of distributing
the weight over the entire tow vehicle that creates a bond
between the trailer and vehicle. Even minor changes in the
adjustment of the hitch can cause dramatic improvements
in handling so it is well worth the effort to make sure
it is correct. It is not rocket science so let me take you
through it. The goal is to have the trailer riding level
and the tow vehicle going straight down when the trailer
is connected. By straight down I mean the front of the car
will be pushed down from the weight of the trailer just
as much as the back. This is not something you do every
time you hook up just when you change tow vehicles or trailer
or when you do something that substantially changes loading
or if you make suspension changes such as new springs.
1) The first thing to check is that your ball is in as
close to the back bumper as possible. If it can go in closer
you should get an expert hitch installer to re-drill the
2" solid square section of the hitch and if necessary cut
it to allow the ball to be as close as possible to the bumper.
Even a couple of inches here will make a difference. At
our dealership we use welded ball mounts whenever possible
because they allow the ball to be closer to the bumper.
 Try
to have your rig loaded pretty similar to how it is when
you normally travel. For better balance, if the water tank
is in the front fill it, if it is in the back empty it.
The only way to really adjust everything properly is to
park the combination on a very flat surface, such as a concrete
pad.
2) Park the unit in a straight line on the level pad.
3) Disconnect the trailer and move the tow vehicle forward
6". (Page Top)
4) Level the trailer: If the "A" Frame is level with the
main frame rails then I usually measure to the bottom of
the frame between the wheels and to the bottom of the "A"
frame just behind the ball. Then measure from the ground
to the top of the coupler to determine the ball height
5) Measure from the ground to the top of the ball on the
tow vehicle - it should be equal to or 1/2" higher than
the trailer ball height. This is especially critical if
the trailer has independent suspension. If the trailer has
leaf springs, the ball can be an inch or two lower. The
weight between the front and rear axles is equalized on
units with leaf springs.
6) Next check the angle on the ball mount. The ball mount
should angle back as much as possible. This angle on the
ball mount acts like the forks of a bicycle - it makes the
unit want to stay in a straight ahead position (that is
why you can ride a bike with no hands).
To check the angle, install a torsion bar in the ball mount
and swing it parallel to the trailer frame. The end of the
bar should be 4-5" off the ground when you lift it enough
to take all the play out of it. If the ball height is over
22" then the bars can be a higher off the ground.
7) Back-up the tow vehicle so that the ball is under the
coupler, but do not put any weight on the ball. Put some
masking tape on each corner of the car and mark a convenient
spot. Here we used 19". Now we know how the vehicle sits
by itself.
8) We are now ready to start connecting the combination.
Lower the trailer onto the ball and connect the torsion
bars to the link that you think might be correct (likely
the first or second link) and lower the weight onto the
car. If you are connecting a vehicle with independent rear
suspension do not raise the back of the car to connect the
torsion bars, instead use a jack under the torsion bar if
you need help to get the chain swung up.
9) Now measure the vehicle where you marked it and see
how much it has been pushed down. It should go down evenly
on all four corners. If it is down more at the back then
you need more pressure on the torsion bars so you would
reconnect using the next link. (Page
Top)
10) Often you will hook up and the back will be down say
1 1/2" and the front will be up 1/2" but it you pull up
the next link the back might be even and the front down
1" so you need something in between, you need a way to adjust
a partial link. A 1/2" bolt pushed through two overlapping
links is a 1/3 of a link of adjustment. So you can use one
or two bolts in the chain to create 1/3 or 2/3 link of adjustment.
11) If the vehicle does not drop evenly side to side then
you can put more pressure on one bar to compensate. The
right hand torsion bar will affect the left front of the
car and vice versa. Especially on pickup trucks due to the
flex in the chassis the back end may twist in relation to
the front. In this case the front is the most important.
12) If you cannot get the front of the vehicle pushed down
no matter how far you do the bars up then the torsion bars
are likely too light or the receiver on the vehicle is twisting
and needs to be stronger.
13) Once you have everything set, mark the link you connect
for future reference. We use a cable tie but a dab of paint
or nail polish is a popular method. On a new hitch, the
bars will work-in quite quickly and after a few hundred
miles you may need to use a bolt to bring the bars up 1/3
of a link.
14) Install your sway control, breakaway cable, chains
and lights, and you are ready to travel.
Once you know what the combination should feel like, you
will notice when the hitch has worked-in further and the
front wheels are not as firmly planted as they should be.
I often will check and adjust the hitch as necessary when
I stop for lunch or gas. Generally you notice the difference
right away when you head back out onto the road.
I know this may seem complicated, but once you have gone
through it a few times you will find hitch adjustment an
easy and simple process. (Page
Top)
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