Toughen your tow rig

Michael Borg — 15 January 2018

Modifying your set-up to tackle the great outdoors is just part of the game these days. Sure, you can head for the scrub with a bog-stock vehicle and a camper trailer dragged straight off the showroom floor, but a few well appointed upgrades and accessories could make your adventure more comfortable and a lot safer in the long run, especially when it comes to your tow vehicle. While most people tend to lash out on fancy pants 12V upgrades and flash looking camping gizmos for their camper trailer, the poor old 4WD could benefit from a few modifications and accessories too. The big question is – where do you start? And what can realistically wait until you win the Lotto? To help clear the fogginess, we thought we’d take a closer look at the kind of upgrades your 4WD will need to totally revolutionise the way it performs on your next adventure, without going to the extreme!


Most brand new 4WDs are fitted with a set of Highway Terrain tyres. They’re cheap and perform well on the bitumen, which is where you’ll test drive one before you buy it, right? The problem is they’re about as unseemly as camouflaged underwear when it comes to offroad touring, with things like all terrain grip, puncture resistance and strength taking a dive. So it makes sense to upgrade to some tougher rubber. Believe it or not, there are actually quite a few things to consider before you lay down your hard earned cash. For example, most people like to increase the tyre’s size over factory fitted dimensions. The benefit is usually increased ground clearance and a larger footprint for added traction. The downside can be decreased acceleration, inaccurate speedometer, diminished braking capacity and extra load or stress applied to wheel bearing and driveline components. Not to mention the added weight of big tyres, and there’s a good chance the spare tyre won’t fit the undercarriage mount anymore either. What’s the answer? Well, for touring purposes a size increase of an inch or two seems to be the best compromise. And thanks to a million Australian Design Rules and regulations, you really don’t want to stray too far from standard these days anyway. Plus, matching your vehicles tyres to your camper trailer rubber means you’ve got more options in terms of spare tyres for those bigger trips too. What size tyre do you think an outback roadhouse would stock? An massive 37in rock crawler, or a fairly standard size all terrain tyre?

The type of tyre is the next consideration to make. You’ve got All-Terrain tyres, Mud-Terrain tyres, Light Truck or Passenger construction – the list goes on. All-Terrain tyres are a good middle ground between Highway Terrain and full blown Mud Terrain tyres. They’re usually of Light Truck construction, which provides plenty of strength, and are designed to perform well over a variety of different terrain while still maintaining decent on-road performance too. You’ll need to keep in mind that the chosen tyre must meet the specifications as per your vehicles tyre place card, with things like the Load Range and Speed Rating being adhered too. Oh, and if you plan on doing a GVM upgrade to your vehicle, the tyres must also carry the appropriate rating to be legal.    


There’s a better than average chance you’ll need to upgrade your suspension to help with the added weight of a fully loaded 4WD and camper trailer. These days campers seem to be fairly heavy on the tow ball, and when you load the back of your 4WD up to the hilt it tends to sag more than a worn out hammock with low self esteem. The good news is there are plenty of aftermarket suspension options to help bring it all back to life. But here’s a tip – wait until you’ve fitted the rest of your 4WD out with accessories first, then get your vehicle weighed while it’s fully loaded before you jump in the deep end. That way you’ll get a grasp around what suspension you’ll need to support the increased load properly, or more importantly, what “spring rate” you’ll require. Weigh the front and rear axle independently too; Things like steel bull bars and chunky winches can rack up extra front-end weight quicker than you would think, and who knows what the rear axle weight would come to.


Modern 4WDs are getting pretty darn heavy these days, and the trade-off is their payload takes the hit. It’s not uncommon for modern day 4WDs to have a lousy payload of around 500-600kg, which is bugger-all once you add a few basic upgrades, a couple of festively plump mates and a full tank of fuel, not to mention a camper trailer hanging off the ball. If you plan on adding a chunk of after-market accessories to your rig, it’s definitely worth looking into a GVM upgrade for your chosen vehicle. It’s not easy to work your way through the red tape, but it sure beats giving your insurance company a way out in the event of an accident, that’s for sure.


Filtering out contaminants like grit or water has always been a big part of 4WD touring, but with modern day common rail technology, good clean diesel fuel is more important now than ever before. Truth be told, there are a million different schools of thought about adding a second fuel filter to the mix. The thing is diesel fuel systems are quite complex these days, and adding the incorrect filter in the wrong place can end up causing more problems. The problem usually lies in poor quality after-market filters wreaking havoc on the fuel pressure/delivery requirements. Each and every vehicle’s requirements are different. So do your research, and if in doubt, regularly replacing the factory fuel filter is a great habit to keep on top of things.


We’ve all seen the photos of an overloaded late model utility with the tray hanging off the back and the chassis snapped in two, right? Well, it’s a pretty common sight these days, which has created a demand for much needed chassis strengthening options. There’s a heck of a lot of factors to consider before you break-out the welder, though. So it’s important to enlist the help of a professional engineer to sort out where the weak points are and the most efficient way to strengthen it up. It could be via after-market bracing or even ute tray mounts that help spread the load more evenly or fishplates.

Dual cab utes are the biggest culprits for chassis cracks. Thanks to plenty of storage space they’re usually loaded to the hilt, with the bulk of the weight positioned well past the rear axle. It’s a bit like doing a push-up with a dumbbell on your head – your neck will ache, much like your chassis does! When it comes to after-market ute chop conversions, don’t underestimate how much strength the roof of the cabin can add to the overall package from standard. Cutting the wagons main roof in two typically adds pressure to different parts of the chassis that are often not designed to handle increased loads.  


There are not many camper trailers around these days that aren’t fitted with an auxiliary battery, which means your vehicle should be fitted with a charging cable to help keep the batteries charged while you’re driving. How do you do that? Well, you’ll need to have a dual battery system set-up in your vehicle first. The idea is to run the auxiliary charging cables from the rear of your vehicle to the auxiliary battery in your engine bay, so that it’s also isolated from your vehicles start battery – we don’t want the camper draining the car battery overnight now, do we? If you’ve got a late model vehicle you’ll need a DC-DC charger to help bump up the charge rate from the alternator. Without a DC-DC it’ll receive a mere dribble of charge over the course of full day’s drive.

With voltage drop being a potential issue thanks to the length of the charging cable, you’ll need the right diameter (thickness) cable for the job too. Typically a 6B&S cable will get the job done just nicely for your average vehicle, but the longer the overall length, the thicker it’ll need to be. Install an Anderson plug at the end of your 4WD for your camper to plug into, and make sure it’s wrapped in conduit, secured properly and routed safely away from heat and debris too.


The real beauty about late model vehicles these days is just how easy it is to get a bit more pulling power! Installing a snorkel is a good start. It delivers cool air to your air intake, and helps protect your engine from sucking up a mouth full of water. Add in an upgraded exhaust system and a custom computer tune and you can have some absolutely massive gains in torque and horsepower. But the best part is you can choose how that power is delivered. In other words if you want low down stump pulling power, no worries, just opt for that type of tune. 

Now, there are a few things to keep in mind here. The first being the effects the extra power can have on your drive train. You see, adding power places more load on the rest of your vehicles components, which can affect their respective lifespan. How much? Well, that depends on a few factors. But put it this way, your warranty is almost always going to be affected. Fuel consumption is another consideration to make, and more importantly do your research into how safe the tune is. Is it within factory limitations? Does it push the boundaries of the engine and its accessories a tad too far?


It’s hard to decide which upgrades you need to do first. But if you ask me, common sense says to prioritise the safety side of things up front. Plan your upgrades, and take into consideration your real world needs versus your dream wish list. One thing’s for sure; get it right and it’ll take your next adventure to a whole new level!

Check out the full feature in issue #121 of Camper Trailer Australia magazine. Subscribe today for all the latest camper trailer news, reviews and travel inspiration. 


test_Toughen your tow rig tow camper camper trailer camping 4x4 4wd offroad engineering bush mechanic