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off-road couplings
The majority of members in the
Australian CamperTrailers Group own an off-road vehicle together with a purpose
built off-road camper trailer & prefer to venture off the beaten
track into the more remote parts of Australia. For this reason they
have an off-road tow coupling which suits the capabilities of both
vehicle & camper. Let's look at what off-road hitches are on the
market & what sort of job they do.
An on-road BALL COUPLING has limited
movement & therefore is not generally suited to off-road use. This
diagram on left shows the limited vertical movement. Major trouble can develop with this
type of coupling off-road if the tongue bottoms out into the hitches
casting & breaks a piece out of the coupling, rendering it useless.
Ball couplings as shown right with hydraulic over-rider brakes have
a 360 degree swivel sideways.
  
The PINTLE HOOK has its origins in agriculture
& then developed for military purposes in the 1940's. The pintle
coupling is not as
popular as it once was. It does have limited movement from
side to side & can be noisy at
times over rough terrain.
An improvement on the Pintle Hook is Vehicle Components
VC COUPLING which
represents a major breakthrough in the performance of ring type
couplings. The key to its ingenious design is separating the ball
movement from the clamp.
The coupling locks a conventional ring into place so there is
no play in-between the towing vehicle and the trailer. The base of
the coupling incorporates a sealed ball joint which provides the
articulation between the two vehicles.
As the movement is fully sealed the coupling can be used in
arduous conditions needing no maintenance. It does not experience
the excessive wear that a pintle hook and ring gets in such
conditions.
The lack of play in the coupling eliminates noise and damage
between the vehicle and trailer and does not snag when reversing
around tight situations.
Next comes the
TREG type coupling which also includes the similar
TRIGG hitch. It does have a pin that stops
full up & down movement, but this does not seem to worry it. It has
full 360 degree movement from side to side. This type of hitch with
its poly block is the most popular of the modern hitches today.
The
polyurethane block gives some shock absorbing
properties, stops noise &
 vibration from the trailer to the
vehicle. Over 50 percent of members of the CamperTrailers Group own a Treg coupling.
The
ORAC type coupling has full vertical movement, ( shown on
left) & full 360 degrees sideways movement as well. It is of similar
design to the HOLLAND hitch. (At time of writing it can not be verified if Holland
hitches are still made.)
Another off-road hitch is the HYLAND, pictured left, which uses a ball coupling with a difference. The hitch is
manufactured to give
the ball full articulation. It also has full 360 degree sideways
swivel & is far superior to the old ball
hitch in off-road situations.
The Hyland hitch must be used in conjunction with a 3.5 tonne ball
which has a higher stem than the standard 2.5 tonne ball. This
allows for proper fitment of the Hyland hitch over the ball allowing
clearance without fowling the tow tongue.
The AT35 COUPLING (now
discontinued) has a secondary means of automatically locking the primary
locking mechanism in place. It is rated at 3.5 tonnes capacity.
This coupling
incorporates variable rate polyurethane bushes which absorb shock
yet allow the structure to take the maximum loading condition.
Articulation is high (70 deg min) in all combinations of movement.
The low profile design allows maximum clearance for rear opening
doors and can be fitted with most stabilizer systems. The
Vehicle Components standard handbrake is designed to fit to the
rear mounting bolts of the coupling.
An over-ride version of this coupling has been discontinued because
the volume of sales was not viable. There had not been one single
warranty claim.
HITCHMASTER DO25 Drop On 2.5
tonne, is a new design in off road couplings by Vehicle Components.
The two diameter pin & boss arrangement makes it easy to connect just
like a ball coupling. The chamfered area between the two diameters makes
the pin slide through the hole in the coupling at whatever angle the
hitch may be.
The DO25 has a simple hooking up procedure,
just pull the T bar up & rotate until the locking plate moves in under
the pins head. Simply letting go will let the location pin on the
locking plate drop into its hole & at the same time the spring lock
fixes the locking plate also. The Vehicle Components DO25
coupling has been discontinued.
HITCHMASTER DO35 Drop On
3.5 tonne, is a bigger version of the DO25 which was released earlier
this year. The DO35 is rated at 3.5 tonne & has the same safety
features as the DO25 with two separate locking mechanisms.
The machined
surfaces makes hitching up much easier in awkward locations than other
off road couplings that need a pin to be inserted. There is a small poly
block for shock absorption between the trailer & tow vehicle.
The OzHitch
is a simple drop in off-road hitch with a self aligning tool in the
shape of a cradle which lines up perfectly the two halves of the tow
hitch for easy connection. This trailer hitch has some great
advantages in being low profile, fully bushed so no rattles, ADR
accredited, lockable for security, galvanised option and connects in
15 seconds. There are two locking mechanisms and they only take one
hand to operate leaving the other hand to operate the jockey wheel.
The hitches design allows for 85 degrees of movement up and 70
degrees in a downward direction.
UNIGLIDE The McHitch Uniglide
Trailer Coupling uses a universal joint to handle all of movements
well past 90 degrees horizontally and vertically with the twisting
being handled in the rear body by shock absorbing urethane bushes.
The universal joint is the same found in all 4wd Landcruisers while
the joint is held in place by registers and opposite threaded plugs
& end caps which removes any end play. The universal and rear body
are both fully greaseable.
AL-KO
has
released three new off road couplings onto the market which fit a
towball. They feature a patented positive towball latching system that
make connecting a breeze, requiring no pin or hole alignment. The
couplings are ADR compliant meeting Australian Standards & designed &
tested in Australia for Australian conditions.
The three
versions available
are a
2 tonne and 3.5 tonne
fixed intended for used with electric brakes & a 2 tonne overrider for
mechanical or hydraulic braking systems. All feature 360 degree head
articulation.
HITCH-EZY
is an Australian designed easy to
connect off road coupling new on the market. Articulation is 90
degrees up and down with 360 degrees rotation. The
automatic double locking mechanism is easily to released even with
one finger using the incorporated arthritis aid. The hitch can also
be driven while pad locked. Urethane bushes in the main shaft
provide rattle free operation while O-ring seals keep dust and water
out. Rated at 5,000kg.
information by Rob
updated
may
2011
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 NATHAN HITCH
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HYLAND HITCH |
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Thanks to Kate for these
photos
HYLAND HITCH
thanks to
Neil for the photos
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