LIFT ISN’T EVERYTHING

By Evan Spence 11 Min Read

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A mild lift and suspension upgrade is a modification that you will benefit from every time you sit in the driver’s seat. Go too far with the lift though, and things start going backwards very quickly. The key word mentioned here is upgrade by the way, as just seeking more altitude under your vehicle is the wrong way to think. The performance of your suspension is far more important.

Here are five reasons why
we don’t like wild lift kits:

1 A higher centre of gravity will  make your vehicle unstable
2 Big lifts cost money that could be better diverted into accessories that will actually take you further, like lockers or quality tyres
3 Four-wheel drives are tools – they don’t just need to look good. If you’re lifting your vehicle purely for looks, consider a different hobby
4 Driveline angles will suffer meaning increased vibration, excessive component wear and ultimately an unreliable vehicle
5 They flex less; especially vehicles with IFS suspension, as most of the available down travel has been removed

Leaf springs are quite simple, yet it seems that very few people understand how to get them performing off-road. You see all sorts of ridiculous methods being used on the path to leaf spring nirvana, such as heavily arched springs to gain ride height, drop (wacky) shackles, or those who fit overly-extended shackles and wonder why their vehicle now rides terribly. The secret to a good ride and off-road performance from a leaf spring revolves around the shackle angle and spring length, then matching a shock absorber that is long enough on extension and compression.

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A vertical shackle will ride firmly as the spring is unable to compress. Go too far flat and you will be on a one way trip to body roll city. So how do you get it right? A 45 degree shackle angle is what all the cool kids run.

Many raised leaf springs are actually shorter than stock, and have additional radius (arch) built into them to simply achieve a lift. This is lazy engineering and cost cutting at its finest. A good aftermarket leaf spring will be longer than stock, keeping the shackle angle at its happy place while still providing a lift. If you crave even more articulation, some hard-core guys will cut off the leaf spring shackle mount, move them forward and re-weld to the chassis to avoid vertical shackle syndrome. Needless to say this modification will require engineering approval, and is not for the faint of heart.

I’m going to tell you something no suspension manufacturer ever will. Did you know that suspension lift alone is not enough to fit larger tyres to your four-wheel drive? Every vehicle will have bump stops fitted from the factory. These small rubber blocks are used to limit the amount of suspension up-travel, which prevents the tyres traveling into the wheel well too far, causing body damage. They are also used to absorb high-speed impacts and bumps progressively too. In IFS vehicles, bump stops are incorporated to ensure the amount of down-travel doesn’t exceed the working limitations of the CV joints or ball joints. So why do we keep forgetting them? Why is it that few suspension manufacturers offer extended bump stops with their kits?

If, for example, you install a two-inch lift kit, while articulating, the vehicle might not even reach the factory bump stops anymore. Coil spring destroying coil bind and inversion of leaf springs will occur, and you will actually get less suspension up-travel, as the axle is not being forced downwards where it belongs (known as forced articulation). Worst of all, if you have fitted larger tyres they will still rub, as the wheel will want to push to the factory bump stop despite having a lift kit installed.

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The other benefit of fitting extended bump stops is being able to install longer shock absorbers, which hold more oil, therefore resist cavitation (shock fade) while working hard off-road. In summary, ask your suspension expert why they don’t provide extended bump stops, and if they claim it is for additional up-travel, walk away…

While lifting your truck has a range of benefits for the off-roader, it also affects the suspension geometry that factory engineers spent a lot of time getting right. The result? It can turn an easy-to-drive 4X4 into an absolute pig, both on and off the tracks, yet so many people are content bolting in longer springs and shocks and calling it good, despite the dangers.

On a solid front axle equipped vehicle you’re playing with the caster, pinion angle, driveshaft angles, brake line length, centre of gravity, Panhard rod angle and changing the range of movement within the suspension bushes to name the big ticket items. IFS rigs will need to look at camber through the range of movement, ball joint angle, half-shaft (CV) angles, and tie-rod alignment. As you’ve probably guessed, this is not stuff you want to wade into without knowing what you’re doing.

There are a fair few ways to correct your steering angles and suspension geometry for just about any lift these days. Sure, it may cost extra, but having steering and handling that’s as good as, if not better than, the factory setup is worth it.

Keep in mind that significantly altering your ride height will always bring about a degree of compromise in the way your vehicle drives, so don’t be surprised when your lifted, big-tyred truck no longer accelerates, stops, turns or drives in general like it did off the showroom floor.

Airbag helper springs, particularly those fitted to utes, have copped a fair amount of bad press lately and it’s largely undeserved. The problem is that people fit them up and mistakenly assume that their vehicle’s gross vehicle mass (how much weight you can carry) has magically been increased, when all the airbag is designed for is to compensate for the extra weight that’s still within the GVM when you’re loaded up for touring or towing.

Folks go ahead and throw everything including the kitchen sink onboard, then hitch up their deluxe multi–axle caravans and head off touring and then turn around and wonder why it doesn’t last. Y’see, by adding an airbag to a chassis that’s well in excess of its GVM, you’re basically adding a stress locating point. In other words: hit a big enough bump at speed in an overloaded vehicle – that’s where she’s going to bend. Which is exactly what happens. Hardly the airbag’s fault, I reckon…

We’ve been hearing it for years now.
“If you want flex then remove your sway bars!” And while strictly speaking it’s true, for anything other than a rock crawler, flex is a vastly overrated piece of a much bigger puzzle.

Take a GQ Patrol for example: Ditch the sway bars and all of a sudden the rear end is flexier than a drunken gymnast. Only, your body roll is now 400 per cent worse, and the front end is actually flexing less. All of sudden you’ve got a poorly balanced truck that looks great on the travel ramp for no noticeable gain off-road. Hot tip: keep the rear sway bar in – the extra resistance actually forces the front end to work.

You won’t win a ramp-off with your mate in his slinky-mobile, but yours will drive a whole lot nicer, and probably further, too.

The moral of the story? Your sway bars are an integral part of your suspension and are there for a host of very good reasons – leave them on. Traction and balance trump a few extra inches of largely unusable flex every time in the real world.

Back in the ’90s, large lift kits on solid axle four-wheel drives were as common as bad mullet haircuts and barbed wire armband tattoos. Thanks to modern traction aids and independent suspension, these lifts are no longer necessary, or even really possible to achieve. When you raise a vehicle, driveline angles change. These could range from the CV joints in the front of your truck, as well as driveshafts in the front or rear, as universal joints have a limited range of movement.

Consider fitting a diff drop kit to the front diff of an IFS vehicle if you have raised it, as this will reduce the severity of the angle placed on the moving driveline components. With leaf sprung vehicles, castor wedges can be installed under the spring plate to change the diff’s pinion angle, and adjustable upper or lower control arms are used with coil-sprung applications to bring driveline angles as close as possible to factory. Get it right, and you will notice less vibration, and provide these components a fighting chance at lasting the distance on or off-road.

Words and pics by Unsealed 4X4, additional pics by Kirsten Nutting


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