We all want a unique vehicle, which makes sense as we all do different things with them. Modifying four-wheel drives is nothing new, and in-fact the off-road aftermarket industry is booming in Australia. But don’t for a minute think that everything available to purchase for your pride and joy is up to scratch or even legal to run on-road.
If you look closely, some off-road accessory manufacturers will (in small print none the less) specify a product is fit for off-road use only. What this means is that no matter how sturdy the construction might be, the product is either unfit for use on-road, or hasn’t been tested to meet the relevant Australian standards required to be approved for legal road use applications. Or more importantly, the manufacturer didn’t want to pay to have the certification performed.
The actual correct fitting of accessories can be equally important, as there are right and wrong ways to fit items in a roadworthy manner. It can be a confusing process to ascertain the correct information, as laws vary state-by-state. Always check with your local roads and traffic authority to ensure compliance before spinning a single spanner. In saying that, what we have assembled here is a concise guide to roadworthy four-wheel drive modifications in Australia.
WHEELS AND TYRES
Every state in Australia will have its own rulings here as to how big an increase you can make when it comes to tyre size. Not only that, but the track width increases are scrutinised also. As a rule of thumb, tyres with an overall increased diameter of 50mm are considered legal, as is a track width increase of up to 25mm. Again, this is all dependent on the state you live in, however this is what is listed in the NCOP (National Code of Practices) which has been adopted as the governing regulatory document throughout most of Australia.
LED LIGHT BARS /DRIVING LIGHTS
It seems every four-wheel drive these days has some sort of LED light installed. Be it a light bar on the bull bar, or a few smaller units to use as reverse and camping lights. But did you even think about the legal ramifications of fitting these lights? Or more importantly, did the company you purchased the fixture from mention legalities?
Thankfully, authorities have cottoned on to the fact LED lighting provides far safer and brighter driving conditions once the sun goes down. In the past it has always been required that driving lights are to be fitted in pairs, which is what caused issues when it came time to pass laws on LED light bars. You can usually only fit one!
The good news is these laws have been changed in South Australia and Queensland – with many states about to follow suit – meaning that LED light bars will be allowed as a legitimate safety item. There will be plenty of discussion on this topic this year no doubt, hopefully with some more positive outcomes for four-wheel drivers. With that said, they must not be installed on top of a bull bar or where vision can be obstructed. This is one rule that applies Australia wide.
In my opinion, one of the most dangerous modifications is incorrectly installing accessories to protrude forward of a front bull bar. Any protruding sharp edges or objects mounted about the bonnet line are considered potential pedestrian hazards and may also interfere with the operation of any airbags fitted to your four-wheel drive. Think fishing rod holders, driving lights, recovery hooks and you will know what I’m on about.
Many moons ago when I was working in an off-road modification workshop, a customer proudly displayed his latest modification. A piece of checker plate steel bolted on top of his bulbar, with his new (and expensive) driving lights bolted to it… sticking out about 30cm forward of the bull bar. When I explained to him how much damage it would do if he hit someone, he sheepishly removed the offending steel and asked us to do it right.
Two simple clamp brackets were all we required to relocate the lights, which actually cost less than the materials old mate purchased to make his cow-catcher. The moral of the story? Buy the right parts to fit the space you have, and if in doubt consult an expert before drilling or bolting anything on.
WEIGHT AND GVM
Weight is a hot topic, and one we as four-wheel drivers often get wrong thanks to the seemingly invincible feeling our vehicles offer. Take a family of five, a loaded fridge, full tank of fuel, water jerry cans and food for a trip, and you have added around 450kg. Now, bolt on a winch, steel bull bar, rear tyre carrier, a fridge slide, dual batteries and side rails and lets call that 250kg.
You now have 700kg of additional weight to carry and we are being conservative here! Now, if you have a vehicle such as the 200 Series LandCruiser with a GVM of 3300kg and a TARE weight of 2640kg, your four-wheel drive is now overweight and un-roadworthy as the allowable payload is only 660kg.
ENGINE MANAGEMENT SYSTEMS AND EMMISSIONS
Older vehicles were far simpler, especially when it came to emissions control. Now we have catalytic converters, diesel particulate filters (DPF), exhaust gas recirculation (EGR) valves and all sorts of measures to ensure emission levels are at all time lows. It is completely illegal to modify any emission control units; so don’t be tempted into playing the emission modification game.
We hear of people blanking off EGR valves to reduce carbon build-ups as these system forces spent exhaust gas back into the engine so it is burnt off rather then emitted into the atmosphere. The same goes with diesel particulate filters, which have been reported to cause issues if you do lots of short runs not enabling the vehicle to reach critical operating temperatures. We can understand the science behind these modifications, however if you want to keep your vehicle in legal roadworthy condition, the only way is to keep emission control units the same as they rolled off the factory floor.
Suspension upgrades are one of the first modifications many four-wheel drivers make to their vehicles, and there’s a staggering array of kits available on the market. With so many options, how do you know what you can and can’t do to your vehicle’s suspension to retain legal roadworthy operation? To make things easier, the below points highlight some common do’s and don’ts when it comes to suspension modifications in Australia.
- As a rule of thumb, a 2in lift (50mm) requires no engineering or additional paperwork and is generally considered a safe modification.
- Extended or adjustable shackles aren’t roadworthy if used to raise a leaf sprung four-wheel drive.
- Leaf spring lift (or lowering) blocks can be used if constructed from solid steel, aluminium or a similar grade material and are positively located to the axle spigot hole and leaf spring centre bolt.
- The use of coil spacers and strut spacers is not roadworthy in most states. If you need more height, use the right spring for your needs.
- Airbag helper springs may be fitted in addition to the original suspension, however coil or leaf springs must have the same or higher spring rate than stock.
If your vehicle has airbags, fitting a custom bull bar without ADR certification is a big no-no. The same goes for bolting steel rock sliders on trucks with side airbags. This is because the barwork may interfere with the safe operation of the airbag system in the event of an accident.
In many cases, crumple zones need to be engineered into the mounting points, just like a bulbar, to ensure the step/rail/slider moves with the impact rather than resists it. The big name suppliers such as ARB, Opposite Lock and TJM have this covered, so if you want safe and legal protection it’s best to check with them. Backyard or custom units are best left to older trucks where there is no risk of airbag deployment failure.
Did you know the maximum width a roof rack is allowed in total is 2.5m? Not only that, but the rack cannot hang more than 150mm past the sides of the vehicle. Keep this in mind if shopping for a second hand unit, or a roof rack that might fit but has been designed for a different vehicle.
Also consider the weight of the roof rack or cage you have your eye on. Vehicle manufacturers will supply a safe working limit that the roof can accommodate while stationary, usually up to the 100kg range. If you bolt on a steel roof cage that weighs 50kg, and put a larger tyre on a steel rim and a jerry can of water on the rack, you’re going to be close to, if not over this working limit. Forget about fitting a roof top tent! Alloy roof racks help out here as they offer the strength of steel without the weight.
Suspension lifts over 50mm will require engineering
Tyre diameter must not increase over 50mm
(i.e. 31in to 33in)
ADR approved bull bars
must be fitted to vehicles
All driving light fixtures
must be fitted in pairs
Roof racks can’t extend 150mm past each side of the vehicle
Accessories fitted must not protrude forward (i.e. driving lights on a bull bar)
Rock sliders need to be ADR approved if fitted to a vehicle with side airbags
Never remove or blank
EGR valves or bypass emission controls
Bolt-on wheel spacers
are not roadworthy
Any modifications exceeding these limits will need engineering approval
Words By Evan Spence