Free Camping: Tow Hitches & Couplings
One of the best things about free camping is that you can get away from the hustle and bustle of city life to kick back and enjoy the natural surroundings. That doesn’t mean you have to rough it, because taking your RV means that you can take your creature comforts with you.
However, the closer you get to nature, the more primitive the roads are that lead to these campsites. This can mean that a standard road going towing setup might not be up to the job.
In this article we’ll explain the different types of towing hitches and couplings that are available and which ones are best suited to free camping applications.
ONROAD AND OFFROAD COUPLINGS
The standard 50mm towball and fixed trailer coupling have been successfully used for many years for towing all manner of trailers and caravans all over the country, so why are offroad couplings needed?
The need arises because of the limited amount of movement between the tug and the trailer that a standard 50mm ball and fixed coupling allows. When towing offroad, the angles that can develop between the tug and the trailer can often exceed the angles that an onroad coupling can handle.
The end result in these situations is that usually something either bends or breaks. It’s even worse if things don’t break when would have been better if they had, like when the trailer rolls over onto its side and takes the tug with it.
Both onroad and offroad couplings provide plenty of side-to-side movement in the horizontal plane centred about the tow ball or tow pin. This is necessary for all couplings to enable the rig to turn corners. However, onroad couplings allow limited vertical movement, which can be easily exceeded by driving through a sharp creek crossing or a washout on a dirt road.
Onroad couplings also allow limited longitudinal rotation between the tug and the trailer. This isn’t important when onroad because the road surface is relatively flat. However, when off road, the camber on the road can change very quickly so that the tug is leaning to the right while the trailer is leaning to the left. An example of this is when towing on a rutted road where the offside side wheels are in one rut and the trailer’s nearside wheels are in another rut. In this case the tug and the trailer are leaning in opposite directions.
Offroad couplings overcome both these problems to allow much larger vertical angles (up to 90 degrees up and down) and (usually) unlimited longitudinal rotation.
WEIGHT DISTRIBUTION HITCHES
A weight distribution hitch (WDH) is an important safety device which transfers some of the towball weight back onto the front wheels. Without a WDH, any weight applied to the towbar will remove weight from the front wheels. This can adversely affect steering and braking and drive traction on front wheel drive cars.
It is highly recommended that WDH be fitted when towing heavy trailers and caravans when conditions allow. This includes all onroad towing and towing on smooth well maintained unsealed roads that do not have washouts, dish gutters or major corrugations. However, be aware that some vehicle manufacturers do not permit the use of a WDH on their vehicles. Also, some towbars and offroad trailer couplings are not designed to be used with a WDH, even when towing onroad.
Most importantly, a WDH should not be used when driving offroad where severe corrugations or large vertical and longitudinal angles between the tug and trailer can arise. This is because the forces generated in the spring bars in these conditions can be much larger than would be generated on road and will often exceed the design specifications of the WDH, towbar or vehicle chassis. This could result in a fractured A-frame, broken WDH spring bars or hitch, broken coupling or towbar or even having the towbar torn from the chassis.
HITCHING UP
Read our 10-step guide to hitching HERE
DROP MOUNT
With the popularity of offroad caravans and the large 4WDs that tow them, there is often a disparity between the height of the towball and the height of the tow coupling on the caravan. This is almost certain to happen if the 4WD has had a suspension lift.
This height difference can usually be easily resolved by fitting an adjustable ball mount (aka ‘drop mount’). These devices have a number of mounting holes which are used to change the height of the towball. To change the height, simply remove both adjustment bolts, reposition the ball mount, then reinsert and retighten the bolts.
Note that if a WDH is fitted, the mounting head will normally provide sufficient height adjustment so an adjustable ball mount will not be required.
TOWBALL HEIGHT
Be aware that you can’t simply mount the towball at an arbitrary height. Road and traffic regulation VSB 1 dictates that when complying with ADR 62/01
“ball couplings on towbars are required to be installed so that the height of the centre of the body of the ball coupling is between 350mm and 420mm from the ground when laden”.
If complying with ADR 62/02
“the maximum height of the centre of the body of the ball coupling may be increased to 460mm”.
TRAPS FOR THE UNWARY
1. Offroad couplings can vary greatly in profile height. Owners of utes or wagons with drop down tailgates need to ensure that there will be sufficient clearance between the top of the coupling and the tailgate when it’s in the ‘dropped’ position.
2. Some offroad couplings require an extended towball or spacer plate to ensure that they don’t bind on the towball or its mount.
3. Some offroad couplings are not designed to be used with a WDH even when towing onroad.
