Tow like a Pro

Steve Cassano — 21 March 2019
4WD whizz Steve Cassano enters the camper trailer world, delivering a few fundamentals to help get the tow on the road.

If you're reading this, it’s most likely that you’re either a camper trailer enthusiast or you’re contemplating the camper trailer lifestyle. Whatever the case, you’re in the right place; Camper magazine has grown to be a reliable, wonderful and entertaining source for all things camper trailer. Over many years, the knowledgeable contributors who live and breathe campers have conducted hundreds of camper and hybrid reviews, openly sharing their expertise for all to read.

I, on the other hand, am a real 4WD tragic. That has historically been my domain, my speciality. Of course, there’s a lot of overlap between camping and 4WD lifestyles; they exist side by side. So naturally I’ve always been interested in campers – but to be honest, when it comes to actually hitching them up, I’m a bit of newbie. Towing I’m familiar with, having hitched up a heck of a lot of boats; but with campers, I’ve only towed a couple over the years, mostly hired ones. I’m hoping that will change from now on. 

After having just read a camper review in the latest edition, I experienced one of those light-bulb moments. It dawned on me that, having plenty of 4WD passion and experience, I could be the perfect candidate to share my experiences and help any newcomers wishing to delve into the camper trailer world – because even though I may not use a conventional tow rig (I’m a Jeeper), I believe the principles are the same. What I’ve written below isn’t meant to be an exhaustive guide, but rather a basic outline to get the towball rolling.


A WEIGHTY CONSIDERATION

We are mainly talking about lightweight camper trailers and hybrids, ranging from about 800kg to 2,000kg on average. The first thing to establish is what the 4WD can capably and legally tow; it’s imperative to know your 4WD’s limitations and be conversant with what your vehicle weighs after adding any mods, accessories, cargo and passengers. Using a local weighbridge or even the local recycling depot can help establish correct weight (saving you from trusting glossy sales brochures and mental arithmetic). 

Personally my 4WD can tow up to 2,000kg with a maximum 4,340kg gross combined mass; and given that, on my most recent camper foray, my intended trailer weighed in at a max of 1,600kg ATM, this was well within the legal and safe limitations. Once all of this is established, and you are in the clear, there still remain a few basic minimum requirements to be fitted.


THE TOW BAR

Naturally you’ll need an approved tow bar, tongue and suitable coupling system. 

When choosing a tow bar, ensure it’s the recommended one for your specific vehicle (some versions can change from year to year) and is rated accordingly; to this end, ensure it’s fitted with a compliance plate. Whilst many tow bars like those for utilities are easily fitted by the average DIYer, others may be more challenging or need a little more expertise, so if in doubt seek proper guidance from the experts. Luckily in my case, a simple OEM (Original Equipment Manufacturer) unit took less than 30 minutes using a few spanners and sockets.  

Once a loaded trailer is attached, the aim is to have the 4WD and trailer remain as horizontal as possible, such that the 4WD’s handling, steering and braking aren’t compromised and remain within safe specifications. When choosing the right tow tongue, take into account any inevitable rear suspension droop due to ball weight once the trailer is hitched. Some forward facing camper trailers are renowned for a heavier tow ball weight than you might expect. 

My 4WD has a moderate, relatively stiff suspension lift, so a tongue with a 4” drop had the whole rig sitting nicely horizontal on my latest trip. If the rear of your 4WD dips significantly once the trailer is hitched – say more than 30mm (depending on the vehicle) – then you’d best address revising the suspension or research possible benefits of the use of air bags, like those from Airbag Man for example. Some of these benefits include the adjustability for different loads and improved handling.

Depending on the type of coupling affixed to the trailer, the 4WD will need a compatible attachment for the tow bar/tongue. There are a myriad of good coupling systems available, some examples being the common tow ball (not recommended for extreme offroad articulation), Treg poly block system, DO35 from Cruisemaster, and XO from ARK.

Finally, don’t forget you need a correctly rated safety chain and shackle for up to 2,500kg trailers (with even stricter requirements on heavier trailers). On the subject of being safety-conscious, depending on your setup, the law may stipulate your vehicle needs additional towing mirrors, because the driver must be able to view 20 metres behind them and four metres either side. Fortunately, with these, you do get what you pay for.


WIRING HARNESS/LOOM

All 4WDs need to be fitted with trailer light connections if towing. Vehicles that will be used to tow over 750kg should be equipped with an effective braking system (with the exception of a few smaller 4WDs that require trailer brakes below the 750kg threshold). 

Most contemporary offroad camper trailers now come with electric or hydraulic brakes as standard, with either disc or drum brakes fitted. There are, however, a few trailers that rely on the old override mechanical or override hydraulic, but they’re becoming a rarity more commonly found on boat trailers.

In order to comply with regulations, the 4WD must have electrical wiring connections to control the trailer lights, such as turn signals, park and stop (strangely reverse is optional). Older vehicles have it simple when wiring up trailer lights, using a basic trailer wiring loom, easily fitted by anyone handy on the tools. Usually splicing into corresponding wires will be all you’ll need to do; this usually has no adverse effect on the rest of the vehicle but please do your research first. About five to six metres of a standard seven core trailer harness with a flat or round seven pin connector and a few terminals should set you back around $30 to $40.

When it comes to modern vehicles with their integrated computer systems, sensors and complex electrical circuits, it does get trickier. In order to integrate the trailer lights seamlessly, you’ll most likely need to purchase a specific wiring kit/harness for your model vehicle. Using the proper kit correctly modifies the behaviour of various systems in many modern vehicles. Failing to choose the right trailer wiring kit and installation procedure can lead to electrical gremlins impacting the vehicle’s behaviour and safety. A specific wiring harness with the correct integrated ECU module can range from as little as $100 for a Ford Ranger, or about $180 for Toyota Prado, to a couple of hundred dollars for some model vehicles. So research your vehicle and choose wisely. 

In my case, as with most camper trailer folks, I opted for a seven core/pin flat layout for the wiring harness. However, there are also five and eleven pin harnesses, but in my case electing the seven pin addressed all the lighting requirements – plus it had the famous blue cable to facilitate the trailer’s electrical brakes.

As mentioned earlier, towing over 750kg requires electric brakes, so you’ll also need to budget for a suitable brake controller unit. There are several good units available on the market; I chose the Tekonsha P2 as it offers great value for money, has a digital readout, can be easily set up (including multiple mounting options), and has some other cool features. The wiring, as shown in the included diagram, is simple to follow and, if applicable, needs to incorporate a harness’s ECU module. You’ll need to budget for about five to six metres of 20 to 30 amp blue cable, a 20 amp auto reset breaker, plus a few terminals. The P2 controller and all parts should set you back about $150 to $200. 


OH, THE VISCOSITY

The final piece in the puzzle is to do with your rear differential. What, you may ask, has the rear diff got to do with towing? Most manufacturers have recommended oil specifications for the diffs; but when it comes to towing heavy rigs and offroading in extreme conditions, manufacturers often suggest oil with different viscosity due to the heavier workload and heat build-up. So make sure to check your user manual for the right oil grade for your 4WD when towing. Don’t let it be like that time your uncle Pete brought hair oil to the barbecue. 


TOWS OVER, FOLKS

So there you are. If you are setting up a tow rig for the first time, I hope this can help you to get started; or if you commonly tow, I hope this was informative or at least reassuring. In the future, I’ll delve deeper into towing, beyond just ensuring you have the correct setup.

For now – happy wheeling.