4WD Sand Driving Techniques.

4WD vehicles are designed to drive through obstacles that conventional (2WD) vehicles would not be able to overcome. Many places in the desert are not negotiable without a 4WD however simply owning such a vehicle does not mean that you can drive it safely. Driving a 4WD vehicle requires a fair degree of understanding about the mechanics of the transmission and the effects that water and dust (common occurrences on offroad tracks) may have upon your safe progress. Every owner of a 4WD vehicle should check these essential skills and practise them before going offroad.

Gear Changes

There is no simple rule for what gear you should use to negotiate any particular obstacle ie. water crossings, mud, sand, snow, rock steps. But here are a few tips:

Ruts
Try to keep the vehicle as level as possible for better traction and comfort. If possible, straddle ruts in the road with a wheel each side. In wet conditions it may be safer to drive into the ruts to prevent skidding.

Climbing Hills
Choose a gear that will allow you to get to the top without having to change gear.

Descending Hills
Choose a gear that will allow you to descend at a reasonable pace without excessive use of brakes.

Mud
Try low range 2nd or 3rd gear to prevent excessive wheel spin. Attempt with normal tyre pressures first to bite into the mud to hopefully find the hard surface below.

Sand
You often need high speed and therefore high range 2nd, 3rd or 4th to avoid getting bogged down. Tyre pressures must be lowered so that the vehicle floats on the surface of the sand (start with 20psi – you can go much lower if necessary).

Water Crossings
Don’t! Clutch problems and loss of momentum can cause major dramas.

Transmission Wind-up?
Caused by driving in 4WD on bitumen or non-slip surfaces, the transmission locks and the vehicle will not move forward. It can also be caused by uneven rolling diameters of tyres. If you suspect transmission wind-up is starting, reverse and shift to high 4. You can also jack one wheel off the ground then shift to high 2. Always check that all four tyres either have the same pressures or at least even diameter (heavy loads in rear often bulge tyres) before engaging 4WD.

Vehicle Recovery

If you’ve never used a snatch-strap, winch, or dead-man-anchor and have no idea what these things are then its a good idea to get onto a 4WD Driver Training Course where you can get hands-on experience using recovery tools and increase your knowledge about what type/size/specification to buy for your vehicle.

On of the most common recovery situation in sand is getting bogged in sand. Thankfully, its also one of the easiest to get out of.

Sand Driving
Sand driving isn’t particularly difficult as long as you obey some basic rules:

Always carry a good quality air compressor. The cheaper variety from your regular car accessory shop is not adequate. These models usually run off the cigarette lighter plug and quickly burn out. Remember it takes about 30mins to inflate all 4 tyres after sand driving to acceptable levels for driving on bitumen. These compressors are only designed to inflate one tyre at a time (handy for a slow leak). The larger capacity air compressors enable tyres to be inflated continuously without overheating and usually in half the time.

Don’t be afraid to deflate your tyres (you can go down to 10psi without damage in soft sand if you absolutely have to)

Never drive over 60km/hr on deflated tyres

Inflate tyres as soon as you pass the soft sections to prolong the life of your tyres

Avoid driving deflated tyres on tarmac (if you have to, keep speed to under 50km/hr).
If you get stuck in sand, firstly check that you have engaged your hubs and are in 4WD. Once stopped, first try reversing over your tracks. If you cannot get out of the bog in reverse in one try, get out and deflate tyres more. Check that the diff is clear – usually by now it is deep in the sand and you’ll need to dig it out with a long-handled spade. If the sand is particularly soft it sometimes helps to clear 4 tracks – one for each tyre. This is also a good method for reversing out of a bog.

Select a gear that will get you out of the bog without digging yourself in further. Try H2. Give it some revs to get out of the bog and onto a firmer patch.

When driving on beaches never park on the wet section of sand. Vehicles have been known to sink into the sand and slip into the sea. Always park your vehicle with the nose pointing to the sea and if doing a u-turn always drive towards the waterline so that the turning tyres are in firmer sand than if you turned with the vehicle positioned nose uphill where the weight of the vehicle would weigh down the driving wheels in the soft sand. If you’re having troubles driving along the beach (parallel to the water line) and find the vehicle is wanting to slip sideways (usually rear to the water), point your wheels to the sea slightly instead of away – its the rear of these heavy vehicles that wants to slip down the slope and doing so will give the vehicle a chance to get enough momentum up to get out of trouble.

ALWAYS carry a tide chart for the beach that you are travelling along and try to travel at low tide.

Creek Crossings

You should never enter a water crossing without knowing its depth and possibly the type of creek bed. Is it rocky, muddy or sandy? Most people get out and walk the crossing first, checking for dips and holes and finding the shallowest path. Central locking should be disengaged and all windows should be DOWN because if the car stalls or electrics short you don’t want to be trapped inside.

If the water level is above tyre height or axle deep you should not cross unless you have prepared your vehicle. A 4WD club can show you how to extend your diff breathers or you can this task done by a 4WD Servicing Mechanic, plus you should use a radiator blind. Essentially, this is a ground sheet wrapped around the front of the car under the bonnet to prevent water flowing back around the radiator and drowning the engine.

You must not change gear whilst travelling through water. So always enter slowly in 4WD low range. Exits are often slippery and steep. Keep going until you are clear of the water and on higher ground. You should stop on your brakes to drain the car of excess water whilst it is still on a slope if possible.

If you do stall and cannot immediately restart you must not continue trying. You will have to be winched out. Check no water has entered the air intake, which will fill the cylinders.

Corrugated Roads
Corrugations can be terrible for both the passenger’s comfort and the vehicle. Nuts, bolts and screws, pipes etc can easily rattle loose in a short period of time. Many outback roads in Australia are heavily corrugated but there are two things that will ease the comfort factor.

Tyre Pressure
To ease the comfort of the ride and to aid in traction on particularly bad corrugations, it is best to reduce tyre pressures about 4 to 6 psi lower than what you run on the tarmac. Very rough and stony country such as the gravel Tracks can handle even softer tyre pressures. This may not seem to make sense at first, but if you consider that your tyre is just like a balloon being bounced over sharp objects then you can see how the higher pressure would make it more prone to “popping”.

Speed
It is also far preferable to keep speed constant and if you feel confident to handle your vehicle in prevailing conditions then try to aim around 60 km/hr. You will find that you can “ride” over the worst of the corrugations at this pace. Any faster can be dangerous, slower and the corrugations may shake you and your vehicle to pieces. There is no perfect tyre or tyre pressure and a combination of luck, speed and driver skill will be the secret to minimising flat tyres and maximising tyre wear.

Suspension
One of the main reasons you would consider altering the suspension on your 4WD vehicle is improved ride. For many people the standard vehicle suspension is just not suitable for the heavy load put upon it when fully geared up for touring – fuel, water and supplies can add up to about a tonne and that’s usually directly over the rear suspension.

Of course, if you’ve already bottomed out your suspension with the load when the vehicle is stationary, imagine what’s going to happened when you hit the corrugations! Adding a few inches of suspension will not only feel more comfortable to the driver and passengers, but it will improve general handling of the vehicle which is a valid safety consideration. For a more detailed discussion on the need for suspension adjustment, see our Suspension article.

Bulldust

Bulldust is a fine talcum powder-like dust that is very common on Desert tracks. It often occurs in areas where the track gets wet then dries and breaks up into fine dust. It is particularly prevalent in areas where it is boggy in the wet season and bone dry in the dry when the majority of traffic breaks up the track.

Bulldust is very deceptive. Looking out your front windscreen it looks like smooth hard patches but in fact it usually is a fine covering of dust over a deep hole. Driving through bulldust at speed is very dangerous – try to avoid bulldust at all times. It can cause damage if sucked into engines too, so in very dusty areas you should have a filter on your air intake and check it regularly. For more information, see our Snorkel article.

4WD Tyres
In regard to safety, tyres play a more important part on a vehicle and trailer than any other single component.

If the tyres are not inflated correctly, or are the wrong type, the stability and ride of the car and trailer combination can be severely effected. Tyre pressures are best checked when cool, hot tyres give an incorrect reading. And don’t forget that tyres on an off-road trailer can be inflated and deflated to suit conditions as you would your 4WD, especially in very soft, hot sand.

4WD Clubs
4WD clubs and organisations are abundant in UAE, which is a comforting thought when first starting out. Most, but not all, clubs offer driver training courses. Driver training is designed to give you confidence in both your vehicle and your own capabilities and limitations. Most courses will also teach you recovery skills such as winching, using a snatch strap, sand driving techniques and can provide opportunities to gain experience in small trips organised by other club members. Dubai offroaders is a good place to imbibe these skills driving with experienced Drivers.

Knowing what you can and can’t do with your 4WD requires a certain amount of skill, loads of practise off-road in all conditions and terrains, and most importantly – confidence. Dubai Offroaders is designed to provide this kind of confidence.