You’ve paid a premium for your 4×4’s multipurpose drivetrain, but what has it bought you? Grant Spolander discusses two sure-fire ways to enhance your vehicle’s off-road prowess
So you have finally embarked on that Botswanan safari you’ve always dreamt of: a flat-plain adventure that hums to the tune of tyres strumming on a sun-baked road.
But then, without warning, the track beneath you gives way to a long stretch of deep sand, your tyres dig down and you quickly lose any momentum. You instinctively reach for your vehicle’s 4WD selection switch and frantically jab your finger at all the traction-aid buttons you can find. But none of it helps, despite the salesman’s assurance that you were buying the best 4×4 by far. Your vehicle rapidly slows to a tyre–spinning halt and you are suddenly stuck in the central Kalahari, a lion just roared nearby and the mercury is at 39°C.
What happened? According to the user manual, you pushed all the right buttons and even had the good sense to deflate your tyres before heading off the tar. But, despite the pamphlet’s lofty promises of unrivalled off-road performance and class-leading 4WD technology, the fact is, your 4×4 is only as capable as its clearance. Once a vehicle’s undercarriage touches terra firma (due to a lack of clearance), it won’t matter how advanced its 4WD systems are – you’re going to get stuck.
There are two modifications that you can make to increase your 4×4’s ground clearance and prevent exactly this from happening again: lifting the suspension and fitting oversized tyres. Both come with their own pros and cons, of course, so the decision should be carefully considered.
Unquestionably the most common modification, the two options available are the add-a-leaf (AAL) system and the aftermarket replacement kit (ARK). The AAL system is most notably the cheapest, but, owing to its increase in spring-pack firmness – and subsequent decrease in ride comfort – it’s seldom recommended first.
The ARK option is extensively used by South African off-road enthusiasts and in Australia. As the name suggests, an ARK upgrade replaces your vehicle’s entire suspension system, including all four springs (leaf or coil), bushes and shock absorbers. Generally speaking, the kits are designed in Australia and provide noticeable improvements to not only ground clearance, but ride quality, weight-carrying capacity and off-road performance. On average, a conventional ARK upgrade will add between 40 and 50 mm of suspension lift to your 4×4. Be wary of kits that offer more than this. As a general rule, anything above 50 mm will probably have adverse effects on the drivetrain, handling and steering geometry.
Arguably, this is the only true way to increase the all-round ground clearance. The shortfall of any suspension-system upgrade is that it can only lift up the components that are supported by the suspension itself. Everything below that point (the solid-axle diff or suspension struts) is unchanged. In other words, a suspension lift only ever increases your vehicle’s chassis height and the related components (sump, fuel tank, bumpers and door sills). Of course, such a lift can still serve an important role by keeping these components out of harm’s way, but it does nothing to raise the lowest parts of your vehicle – those most likely to get hung up on rocks or deep sand. So, to effectively increase overall ground clearance, you need oversized tyres.
The benefits of fitting larger tyres are manifold: bigger tyres will drastically improve both off-road driving comfort (the ease at which a vehicle travels up and over an obstacle) and, even more importantly, the degree of traction (an essential feature that allows a 4×4 to drive off-road).
However, in order for larger tyres to fit within standard-size wheel wells, significant modifications to the fenders are needed. Depending on just which vehicle you own, some trimming of the bodywork may yet be necessary. To complete this type of modification successfully (without the tyres bulging outwards), it is generally advised that custom-made wheel arches be added.
In some instances, fitting oversized tyres may still require the installation of a suspension kit (as well as fender trimming), as this will ensure there is adequate space for the suspension and tyres to flex.
But, no matter which solution you decide on, the bumpy, rocky or sandy road forward will be a far easier one to follow – a path paved in confidence, comfort and peace of mind.
Photography Henrie Snyman
(This article was first published in the summer 2014/2015 issue of AA traveller magazine)