What you need to know before buying 4X4 suspension

By Unsealed 4X4 8 Min Read

It is impossible to not hammer on about the fact that factory-fitted suspension is a compromise. Now I’m not going to say something vague like suspension is one of the most important components on a vehicle. A $0.20 seal in your clutch hydraulics system can result in a call to your local tow truck. Having said that, the reality is suspension would have to be right up there next to having a chassis, engine and steering wheel in terms of importance.

It holds your vehicle up. It determines the ride quality and handling characteristics. And it works harder than a one-armed swimmer to stop you and your occupants from rattling to pieces. Then there is the other side of the coin – for those believing there is a better solution out there than the one that rolled off the new vehicle production line. What should you be looking for in aftermarket suspension, and what do you need to know to keep your 4X4 in a legal and roadworthy state? Well, I’m glad you asked!

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Five questions to ask your suspension guru

  1. How long is the warranty period?
  2. How much lift is safe and legal for my vehicle?
  3. What else should I do while the vehicle is getting work done?
  4. What spring rate would you recommend for my vehicle’s modifications?
  5. Do you have parts back-up Australia-wide?

Five common suspension mistakes

  1. Making purchases based on price rather than needs
  2. Not accurately estimating how much weight you will carry
  3. Wanting to lift the vehicle too high
  4. There is more to it than just springs and shocks
  5. Not getting a wheel alignment post suspension install

Gross vehicle mass

Many four-wheel drivers have overloaded their vehicles without even knowing it. Vehicle manufacturers list strict figures for the amount of weight that can be carried, as well as how much can be towed. Once you add barwork, long-range fuel tanks and camping gear, you would be amazed at how quickly you can reach and exceed your GVM. This is why suspension manufacturers, like The Ultimate Suspension and Terrain Tamer, offer GVM Upgrades.

Are GVM upgrades possible on new and old vehicles?

New, pre-registered vehicles are able to have a GVM upgrade performed and certified, and this is the case in all States of Australia. Used vehicles can have a GVM upgrade performed; however, it is a little trickier as laws do vary from State to State. You will need to consult an authorised engineer in your area first.

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Can any vehicle have a GVM upgrade performed? 

Yes and no. Every vehicle has a GVM issued from the factory; to have the GVM increased there are a series of tests that need to be independently certified, as well as ADRs (Australian Design Rules) which need to be retested. For example, brake testing. This testing is incredibly expensive, which is why most people wouldn’t go through with it. Suspension manufacturers fund this testing when developing GVM upgrades, meaning the consumer won’t have to.

Are there different GVM regulations State by State?

Yes, absolutely. Some States are easier to gain approval than others, and some are notoriously challenging. This only applies to second-hand or pre-registered vehicles though (as mentioned). A new unregistered vehicle can have the GVM upgrade performed by us before you take delivery of it, and this will be considered roadworthy in any State of Australia. Again, consult your engineer and visit your chosen suspension expert to discuss the plan of attack before upgrading the GVM. Or speak with a company that can handle the entire process, including engineering, and drive-in-drive-out, for the ultimate in convenience.

Lifting a modern four-wheel drive legally

This had been a massive issue of contention in the past: Lifting a modern vehicle (made post-2011) that is fitted with Electronic Stability Control. Aside from lifting the suspension, fitting even slightly larger tyres was a no-go also. Well, this all seemed a little ridiculous to the Australian Automotive Aftermarket Association (AAAA for those into acronyms) who spent roughly $250,000 on testing both here and in the USA. The outcome of this testing was that it has been proven that a small increase in ride height, up to 50mm, will not impact the operation of ESC. In fact, according to the supporting document VSB14, it has now been declared that a lift of up to 50mm can be carried out under basic modification without certification.

7 reasons to keep 4×4 suspension low

  1. Droop or down-travel is important, lift reduces the available amount (especially with independent suspension)
  2. Not tipping onto your roof is a good thing (call me old-fashioned)
  3. Being able to access shopping centres or parking stations is nice also
  4. Increased wear on driveline components is the definition of a bad time
  5. Big lifts = poor handling without lots of expensive work and components
  6. Add $1,000 to your budget for every inch of lift past the first inch
  7. Low and wide is the new tall and scary and might even make your 4WD easier to insure as well.

Suspension lift kit packages

A suspension kit or package makes a heck of a lot of sense for a touring four-wheel drive. While for some more extreme applications (think really heavy loads or those wishing to drive tougher tracks) they can be a compromise, it is wise to match components from one manufacturer that are designed to work with each other rather than against. It is the little things – like U-bolts that fit the leaf pack properly. And being supplied the correct amount of suspension bushes that (shock horror) will actually slide into the springs as they should. There is also the bigger issue of matching shock absorber valving with the specified spring rate…

These are things that purchasing a kit or suspension package from a reputable supplier should ensure. If something does go wrong with your vehicle’s suspension, it is also nice to know you only need to make one phone call to one manufacturer to chase the part/s. Simplicity is key when it comes to building a successful touring machine, after all.



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