4WD MODIFICATIONS - GENERAL MODS
Dust. It looks great in the trip photo album or video, but it’s a gritty nuisance when it gets into your last kilogram of flour.
One of the great hassles of Outback travel is the dust that your 4WD and other vehicles kick up. However there are some sealing and driving tricks to minimise dust entry.
As your machine travels through the air it creates pockets of low pressure in the airflow, particularly at the rear end. That’s why dust builds up on your back windows.
Inevitably, the pressure inside the vehicle is lower than that on the frontal surfaces as your 4WD punches through the air, so the dust that’s mixed in with the low pressure air at the rear of the vehicle can be drawn inside.
Tight door and window seals, closed windows and the interior pressurised by the aircon system are keys to preventing dust entry from low-pressure areas.
Your air conditioning system must be in top order, because it’s the only way you can guarantee driving in all conditions with the windows shut. A failed aircon unit and a wagon load of powder-coated people don’t make for a happy campsite.
Dust can get inside your 4WD via the high-pressure ventilation air that enters your vehicle. You need ventilation when you’re driving and sometimes that ventilating air is full of dust. Some 4WDs have fresh air dust and pollen filters, but they’re often-neglected service items. A clogged filter won’t let the ventilation system work properly and you could finish up having to open windows.
The best way to prevent dust laden air pressuring in through the fresh air intakes is to keep out of dust clouds. Don’t sit in someone else’s dust cloud, because you won’t get where you’re going any quicker than if you drop back and enjoy the view and the clear air.
If you’re overtaking in dusty conditions plan your manoeuvre well in advance and do it briskly and cleanly: don’t dilly-dally in the dust cloud getting hammered by stones and with dust filling your vehicle and your engine air cleaner.
If the dust cloud is kicked up by a road train give serious thought to stopping for a break, rather than trying to overtake. If you’re determined to get by, try talking to the road train driver on UHF40.
When you see an oncoming vehicle slow to a crawl as you pass. This action drops the size of your dust cloud and minimises the time you spend driving through the oncoming vehicle’s cloud; in addition to preventing flying stone damage. If it’s an oncoming road train – STOP.
Don’t fling your doors open as soon as you come to a halt. Wait a few seconds for the dust cloud to blow away and you won’t have grit pouring into the vehicle and all over you.
Most 4WDs have a flow-through ventilation system, with flapper valves at the rear end of the cabin. These valves let air out and are supposed to prevent dust entry, but if they don’t work freely they’ll let dust in – lots of it. If you can’t be sure the flow-through ventilation system valves are working properly you can whack some gaffer tape over the flow-through vent outlets before you get into severe dust conditions – that way no dust can creep into the cab through the outlet vents.
Door seals are the main dust entry preventers, so it’s important that they seal tightly all around. If you’ve done a trip and had a dusting, you can usually see from dust traces on the door frames and trims where the stuff got in. If the rubbers are misshapen, you can sometimes restore their original shape by loosening the fasteners and refixing them after manipulating the rubbers.
Hinges wear and door locks get out of adjustment, especially on hard-worked 4WDs, so you may have to reset your door locks to put pressure on the rubbers.
To make sure your rubbers are seating properly you can coat the seals with a thin layer of car polish, open and close the doors and look for a solid line of polish left behind on the door frames. The polish can be rubbed off afterwards and the exercise will ensure that the seals and the door frames are clean, for improved seal seating.
Wagon rear doors are often problematic and the worst offenders are those with spare wheels attached. It’s very difficult to keep a heavy door tight against its seals when running over corrugated roads. All you can do is keep the door well adjusted and replace the seals if they look like they’re over-compressed.
If you make a habit of driving on corrugated roads, give thought to a separate swing-away spare wheel carrier.
Window runner seals also need attention. Make sure that the glasses slide without puckering the seals and that they fit tightly against the top window seals. Lubricating the slides with silicone spray does an excellent job of taking friction out of the system.
Don’t overload your roof rack, because too much roof load can cause distortion of the bodywork and let dust in around the door seals. (Dust entry in these circumstances is only a mild part of the problem you’re likely to face, because cracked door posts will give you more than dust entry to be concerned about!)
Utes have particular dust sealing problems, because ute trays aren’t designed to be dust-tight. Tonneau covers keep out some dust, but it’s wise to pack only dustproof and watertight gear in the back of a covered ute. You can enhance dust resistance by sealing tailgate gaps with foam pads that jam into place as you shut the gate.
A tarpaulin cover needs to be stabilised by throwing a non-elastic cargo net over it, otherwise it’ll flap loose and the dust will have a field day.
Canopies are usually watertight, but dust can creep in around the sides of the ute tailgate. A tarpaulin ‘blind’ laid over the freight at the rear of the tray and the canopy tailgate will help protect the load from dust entry.