What are the different types of
couplings and which one is right for your vehicle and RV?
Couplings – What is a
are five main parts involved in the coupling: the tow bar,
the tow ball and the ball mount or tongue that all attach to
the tow vehicle plus the coupling body and the trailer ‘A’ Frame or
trailer draw bar that form the attachment points on the
Some caravan and camper trailer manufacturers will
provide an option for the type of coupling. There are
various types but the most common is the on-road ball
Standard Quick Release Plunger Coupling
Most caravans and trailers come with a standard
plunger ball mount coupling. These quick release
plunger couplings are not considered to be strong
enough to withstand the rigors of off-road use.
Some of the imported European caravans have a
coupling that incorporates a stabilizer (See article
on Sway Control Devices)
The Hyland hitch, manufactured by Darren Hyland, is made to
give the ball full articulation and it has full 360 degree
sideway swivel so it is often favoured for off-road caravans
and trailers. Proper setting up using a 3.5 tonne ball with
a higher stem is required. The Hyland hitch head can be
padlocked to prevent theft of your RV.
Camper trailers can be taken over much rougher terrain and
the ‘up and down’ movement can be harsh and result in the
bottoming out on the coupling and break either the tow bar,
coupling or tow ball. Options are to use other types
of couplings such as the ‘Treg’ or ‘Orac”
The Treg, Trigg and Orac hitches are often used for camper
trailers and not caravans due to the difficulties
experienced in lining up the hitch pin to the rear of the
tow vehicle. Camper trailers are more likely to be able to
be physically moved to line up the hitch than say the
What is a Treg Hitch /
‘Treg’ hitch has a polyurethane block which has some shock
absorbing properties and stops noise and vibration from the
trailer to the vehicle.
What is a Trigg Poly Block Coupling?
The Trigg hitch is manufactured to ADR by Trigg Bros
Pty Ltd of South Australia, for up to 2 and 3 ton
use is similar to but should not be confused with
the Treg Hitch.
What is an AT35 Coupling?
Although now discontinued, the AT35 hitch coupling is rated to 3,500 kg and provides
high articulation (70 degree min) in all combinations of
movement. The AT35 coupling is often used by 4WD owners
with a camper trailer or all terrain/off-road caravans.
For caravans up to 4.5 tonne you also
have the choice of the sturdier DO45 heavy duty
off-road weight distribution hitch (WDH) compatable
coupling. The DO45 incorporates a double automatic
locking mechanism, plenty of simultaneous
articulation in all directions and a patented
self-aligning pin. New features are the dust cover
which also ensures the coupling is correctly locked
when fitted and a front cushion to prevent damage to
the tow vehicle.
What is an Orac Coupling
‘Orac” type hitch allows full vertical movement and full 360
degree sideways movement as well.
What is a Hitchmaster DO35 Coupling?
Vehicle Components of Geebung,
Queensland, Australia have released their DO35 3.5T
drop on coupling which provides plenty of
articulation for off-road use. Vehicle Components
also provide a number of option kits to suit use
with weight distribution hitches (WDH). The
Hitchmaster DO35 coupling meets all the Australian
Design Rules (ADR) specifications and also has twin
ADR compliant stainless steel locking mechanisms.
What is a McHitch Uniglide Trailer Coupling?
The McHitch Uniglide Trailer Coupling has been invented by an
Australian, Joe McGinnes, as an all purpose coupler for all types of
trailers such as caravans, horse trailers and off road campers. Currently
there are the 3.5 tonne and 6 tonne models with a 10 tonne version on the
way. An important feature of the coupling is the use of a universal joint
to handle all the vertical/horizontal movements with twisting movements
being handled in the rear body by shock absorbing urethane bushes. The full
body and the universal are both fully greaseable. McHitch adaptors are
available for use with some existing market couplings.
What is an OzHitch?
The OzHitch (or 50 second hitch) is an Australian Design Rule
(ADR) and ISO 9001 approved off-road 3.5 ton hitch designed by Norm Hudson.
It is designed with a tolerance for easy connection of the two halves of
the hitch into the cradle. The OzHitch is made from steel and there is a
choice of zinc plated or galvanised. The zinc plated OzHitch more suitable
for painting. The designer states it has a very simple self locking system,
lockable pin for security and a low profile to you’re your vehicle rear
doors from damage. Maintenance involves a pump of grease in the grease
nipple for the joints about every 1,000 km especially if travelling in duty
conditions and some silicone spray on the pin.
What is a
The Hitch-Ezy is a 5 tonne coupling designed by John Allsop and ADR
compliant for the heavy-duty off-road caravan and trailer market.
Hitch-Ezy utilises a patented locking on method and the
designer states this mechanism is easier to operate as the sleeve neither
jams going on or coming off. Hitch-Ezy tows on a tow-pillar not a
tow-ball and therefore does not have ‘slop’ and associated noise or the need
for adjusting screws to remove any ‘slop’. The tow pillar is case
hardened and chromed ball bearings are used. The designer’s opinion is
that having the horizontal axis of rotation of the coupling pass through the
axis of the tow-pillar is an important design feature that improves the ease
of coupling. With Hitch-Ezy you can back the head of the tow-pillar into the
open forward-facing mouth of the coupling's sleeve and it will roll on ready
for descent and full engagement. Subsequent downward forces from a lowered
jockey wheel then act to self align the sleeve to the pillar rather than
fighting against achieving this required alignment.
For off-road use the Hitch-Ezy uses O-ring seals to keep out dust and water
and , when not in use, also comes with an aluminium dust cover and plug to
protect the mechanism. Other features include grease nipples at the rear
(to prevent any stone damage) and a coupling height of 117mm that will allow
for rear door opening on 4WD vehicles whilst coupled to a caravan or