A 4X4 DUAL-CAB ute is, in the ideal world, viewed as the ultimate off-road multi-tool A real jack-of-all-trades when it comes to offering the versatility needed by a large number of tourers. Being able to lug your – or your mate’s – furniture to a new abode, carrying bikes, watercraft, camping gear, the family pan-licker or just the shopping are, along with improvements in ride, handling and safety, some of the reasons behind the explosion in dual-cab sales over the past five years. But the truth is, a dual-cab is still a compromise. A balancing act, if you will, and one that owners strive to get right, in no more important area than being able to take advantage of that load-carrying capacity, while minimising any sacrifice in ride comfort and overall handling when their fourwheel workhorse is trundling around with no load out back.
SUSPENSION is key to ensuring the best middle-ground in terms of balancing the demands of load-lugging with unladen driving. Go too heavy-duty underneath and you and yours will be bounced and bumped all over the place when tootling around town with no load; go too light and, when the time does come to load up, the vehicle’s rear will drop low, impeding ride and handling, with the roll-on effect being a potential compromise to occupant safety.
Tough Dog has come up with a neat solution in the form of its Tough Dog Air Assist Bellows (for leaf springs) and Air Assist High Pressure Bags (coil insert bags) kits. We were lucky enough at 4X4 Of The Year to have Tough Dog boss John Agostino and son Michael accompanying us on the week away, with the fatherand-son combo driving a Toyota Hilux fitted with Tough Dog’s new airbag-based kit. Along with the airbag assist rear-end, the black Tough Dog Hilux sported the best suspension setup the company has to offer: a 40mm lift, via springs and a Tough Dog foam cell strut (40mm internal diameter bore/60mm outer diameter casing and 18mm rod) up front, combined with a set of Tough Dog adjustable rear shocks (with, again, a 40mm ID and 60mm OD casing and 18mm rod) that features nine externally adjustable valve settings, married to a set of Comfort leaf springs and the new airbags (inflated via a valve underneath the towbar). This airbag-assist setup has been in development for a while, kicking off as a result of many customer enquiries as to Tough Dog stepping into the airbag market, as Simon Vella, Tough Dog/4Way Suspension product development manager, explains.
“We’d been receiving calls forever and a day, with people asking ‘why don’t you do airbags?’” Simon explains. “And it was perfectly understandable; if you sell a Comfort spring and the customer wants to put something heavy in there – which is something inconsistent to what they would normally do in the day-to-day – the airbag is obviously a good substitute. So you can put around 30psi in it, as an example, and carry an extra 400kg.”
OTHER tweaks for the 4x4-specific airbags included adding plastic conduit over the air lines to protect them, and making sure placement of things like the bag’s Schrader valve was suited to off-road touring use. Another key modification Tough Dog insisted on was the beefing-up of the airbag bracketry so it, too, would be up to the rougher treatment consistent with an off-road touring scenario. This included additional welds and more gussets to minimise the effect of the increased twisting and vertical movement of an off-road vehicle’s axle. Also included were positional changes; moving the bracketry in-board ensured any owners who fitted wider than standard rolling stock (wheels/tyres) did not foul the wheel/tyre combo and airbag. Some vehicles only required one bracket tweak, others were a bit more involved, but the Tough Dog crew took their time to ensure that each vehiclespecific application was spot-on before approving production.
IF YOU’RE going to test out your new suspension kit offering, it’s hard to beat the route taken during this year’s 4X4 Of The Year test week. From the controlled – and super challenging – environment found at the Melbourne 4x4 Training and Proving Ground, in Werribee, Victoria, through to the varying terrain found through outback Victoria and NSW and then, finally, at Eldee Station, west of Broken Hill, there was plenty of opportunity to find any potential fault in a vehicle’s suspension setup. Befitting the Tough Dog air-assist kits’ focus, John had loaded the Hilux with 600kg of cargo weight in the ute’s tray. This, along with all his and Michael’s gear (plus themselves), meant the Toyota was lugging around 800kg each day, over widely varying terrain.
The Hilux tackled every type of terrain comfortably; the hill climb used on 4X4OTY is something most tourers would look at when out on the tracks and then try and avoid. The Hilux trundled up it without any trouble, with the rear end staying sufficiently above the deep holes to avoid any dragging of the towbar. It repeated this controlled performance on soft, wet sand dunes; the rear end maintaining its standard ride height – and offering less body roll, even with a load on board – saw it negotiate some particularly boggy section of sand with aplomb. On faster, flatter corrugated dirt tracks, the Toyota workhorse was also well controlled, with the load in the tray having little effect on any bump steer from the sharp-edged holes found all along these surfaces. In fact, the Hilux sat quite ‘flat’ even when cornering, a direct result of the airbag fitment out back, and what Simon Vella refers to as ‘trapped air’ inside the bag.
“The one thing you will notice is, because that air is trapped in the bag, it is like you have fitted a heavy-duty swaybar to the vehicle, so it sits flat … very flat,” Simon says. And it did.
ONE THING he mentions does resonate with this kit (and all/any other airbag-assist setups) and that is the consumer needs to know they are going to use it to its optimum benefit. “When you put air in an airbag the air is trapped in basically a rubber bag and cannot go anywhere,” Simon says. “It is stuck in there and you’ve got to run minimal air pressure to retain it as a bump stop, as you are removing the bump stop to put an airbag in there.”
This translates to an unladen vehicle running the equivalent of a quite firm bump stop, something that may not appeal to those whose majority of driving hours are taken up in urban areas, as there is a slight trade-off in ride comfort when it comes to rolling over sharp-edged sections of road (Simon recommends opting for Tough Dog’s adjustable shocks to negate this effect; being able to tweak rebound and compression to account for no load or a full load is worth the extra cost, we reckon). For the general off-road tourer, though, who spends a fair chunk of time off the bitumen, driving a rig loaded with camping gear, canopy, drawers, etc., the ability to obtain similar ride and handling regardless of loadweight, the Tough Dog air-assist kits are a real boon. As Simon Vella says, Tough Dog is not reinventing the wheel with these kits, but being able to buy well-matched components as a complete kit, rather than cobbling together shocks/springs and a perhaps notso-well-matched airbag, makes for an appealing option for the uteborne tourer. Who said a 4x4 dual-cab ute was a compromise?
For more info on the Tough Dog Air Assist Bellows (for leaf springs) and Air Assist High Pressure Bags (coil insert bags) kits, see www.toughdog.com.au