4×4 Modifications: Are Your Mods Street Legal?

4x4 modifications are mods street legal tjm perth blog header

Are you eyeing off that new LED light bar for your 4×4? Maybe you’re thinking of raising your tyres? Lifting your suspension? Depending on what state you live in, this could render your 4×4 street illegal.

Thanks to eBay, Gumtree, and of course, online 4×4 shops that cater to every state in the nation, buying and fitting 4×4 modifications can be legal in one state and illegal in another. For example, in Western Australia, you can support a 50mm larger diameter on your placarded tyre rating, and a maximum 25mm suspension lift. In Victoria and NSW, the state road authorities allow a total lift of 75mm, letting you decide how to “spend” that lift across your tyres and suspension. The libertarian by comparison NT allows 100mm of lift without any engineering certifications. So what else can trip your modification odyssey up?

LED Light Bars

You may have heard that at least in the past, South Australia and Queensland banned LED light bars on 4×4 vehicles. This ban is now lifted, and all LED lights are subject to a national code of conduct. LED Light Bars are restricted from placement on top of a bull bar or where vision may be obstructed.


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Weight and Gross Vehicle Mass (GVM)

Some 4×4 owners think their vehicle can fit the family, camping gear, the kitchen sink, AND tow a huge campervan without breaking a sweat. You should always pay attention to the GVM and TARE weights of your vehicle, because in most cases, the maximum allowable payload is 660kg.

Circumventing Engine Management Systems

Back before emissions standards and environmental protection initiatives, 4WDers had a great time blanking off diesel particulate filters (DPF) and exhaust gas recirculation (EGR) to reduce carbon build-up in engines. However any type of modification to engine management systems is illegal – so don’t even go there.

Roof Racks

The maximum allowable roof rack length is 2.5m, no exceptions. The rack may not hang more than 150mm past the sides of the vehicle.



Pictured: TJM Roof Racks

Bull Bars and Airbags

If your 4WD deploys air bags in case of collision, fitting a non-factory bull bar can interfere with those sensors. You need an ADR certified bull bar, with crumple zones engineered into the mounting points. It’s best to go through a certified dealer than buying something off eBay or Gumtree.

Why Does This Matter?

It matters because if the police pull you over and warrant a full vehicle inspection, it renders your pride and joy unroadworthy until you remove the mods. This means a big hole in your pocket for something you – and most people in Australia – can’t use.

Worse still, if you get into a car accident and the third party alleges (and proves!) that your vehicle’s modifications are illegal; your insurance company will render your policy null and void.  That means you’re stuck with your repair bill, the third party’s repair bill, and potentially any charges relating to driving an unroadworthy vehicle. Because let’s face it; you’re driving an unsafe vehicle according to law. This puts you, your family, and other road users in danger.

In short, if you’re thinking about getting mods done to your 4×4 – check they’re legal first!



TJM Perth

We are a family owned private business that takes pride in providing quality service along with the best quality 4×4 accessories in Perth. We stock all TJM 4×4 accessories along with other top Australian 4wd accessories brands.

If you would like some help in getting the right gear for your 4wd, please feel free to contact us or visit 9 Pritchard St, O’Connor WA 6163 Australia.