EXPLAINED: UPPER CONTROL ARMS
HAVE YOUR UPPER CONTROL ARMS GOT YOU DOWN IN THE DUMPS? AN AFTERMARKET SET MIGHT JUST BE WHAT THE DOCTOR ORDERED.
MODERN independently sprung 4x4s are better in almost every way than their older live-axle ancestors. They’re more comfortable, more capable (thanks to a whole heap of electronics), ride better, use less fuel, and allow us to pound out previously unheard-of kilometres without breaking a sweat. Yep, on paper they’re just about perfect; except all that ‘extra’ stuff comes with ‘extra’ complications. There’s no hiding the obvious ones like needing a degree to even open the bonnet, but one that’s sprung up more and more with modern suspensions is their complication in suspension lifts.
The basic premise still stands. Take out the standard springs, put some longer ones in, and lift the body and chassis of your 4x4 a few inches farther away from the ground. But unlike the comparatively agricultural live-axles, independent suspensions cause all sorts of issues when you start cranking them towards the skies. Aftermarket upper control arms have taken the 4x4 scene by storm, promising to fix what ails you, cure your lifting issues and grow curly hairs on your chest.
To get to the bottom of what’s what, we’ve spoken to some of the biggest names in welding together control arms to find out everything you need to know to not only lift your IFS 4x4 safely, but do it legally as well. We’ve roped in Troy Schipper from Roadsafe, the company behind Blackhawk control arms; Michael Hayes from Superior Engineering and their adjustable arms; and Cal Goodman from Caloffroad.
THE STRAIGHT AND NARROW
WITH more and more 4x4 gear being rolled in glitter and sparkles, it’s almost too easy to get wrapped up in the what and less in the why. Before laying down your credit card details on a set of new upper control arms it’s vital to know why you do (or don’t) need them. Whether your 4x4 is sporting an independent front end or live axle, installing a suspension lift will do two things: it’ll physically lift your chassis and body away from the mounting point of your wheels and tyres, which frees up room for larger tyres and provides ground clearance; and it’ll pivot the suspension arms, linking the two together. In solid axles, that pivot effect is rarely an issue; the axle will roll, changing the relationship between upper and lower bearings and throwing off the caster. A set of off-set bushes will fix the issue without too much fuss. In an independent front suspension things are a little more complicated. The twin-arm arrangement means there’s not only caster adjustment like a solid axle 4x4, but also camber to consider. Lifting an independent 4x4 even minimally can knock all these alignments out of spec and cause issues with ball-joint operating angles, clearance on both tyres, as well as other suspension components. Aftermarket upper control arms are designed to alleviate all these issues, getting the suspension geometry and alignment back to factory or better. Troy from Roadsafe adds another point often overlooked, “When the manufacturer gives a wheel alignment specification, it’s without raised height or increased tyre size. Larger tyres absorb caster, forcing you to run higher caster than stock to retain the same feel.”
AFTERMARKET UPPER CONTROL ARMS HAVE TAKEN THE 4X4 SCENE BY STORM
LONG APPENDAGE OF THE LAW
WHILE Australian Design Rules are a fantastic implement to ensure the car next to you isn’t running plywood suspension arms, the channels for modifications are often murky and fraught with danger. There’s been many people forced to uninstall better handling suspension or better performing brake upgrades because the owner didn’t tick the right boxes. Before a set of control arms can be fitted to your 4x4 they need to be proven to meet or exceed ADRS and OEM (Original Equipment Manufacturer) specifications.
There are two ways this can be done. The first is through the manufacturer itself. If they’ve gone through the process to prove their arms meet or exceed the factory specifications they’ll be able to provide you with the relevant paperwork.
“National Code of Practice classifies these as a direct replacement component,” says Michael from Superior Engineering. In most states this should mean no further paperwork is required; although, if you do require engineering in your state it’s as simple as supplying the paperwork so no further testing is required.
If the manufacturer hasn’t jumped through these hoops it means the arms in their current state aren’t legal for road use, no matter how well (or poorly) they’re built. You’ll need to consult with an engineer and likely spend thousands in destructive testing to ensure they’re up to spec. If the manufacturer can’t provide relevant paperwork you may as well have got the pizza delivery boy to weld them, as far as the law is concerned.
“AFTERMARKET ARMS ARE ONLY LEGAL IF ALL COMPONENTS MEET OR EXCEED OE”