It is important that 4WDrivers understand the operation of free-wheeling hubs and the transfer-box gear selection.
On bitumen or other hard surfaces, the vehicle should be in 2WD, high ratio all the times; and if it is a constant 4WD, in normal gear, the centre diff should not be locked.
Some people engage 4WD as soon as they see dirt, which leads to unnecessary wear and tear, as well as increased fuel consumption. If you can easily manage in 2WD, try to refrain from switching to 4WDriving.
In 4WDs with manual free wheeling hubs, always remember to disengage the hubs and shift back to 2WD as soon as you get onto the bitumen; or you can damage the vehicle.
A 4WD isn't a guarantee that you won't get bogged, but it will help you get bogged less often.The downside is that when you do get bogged, it's normally deeper and further into the quagmire than with a normal car.
These are ruts in the road normally found on gravel and dirt roads. They are not pleasant to drive over and you need to be careful when approaching them. Obviously, going too fast over them can be very dangerous, as well as detrimental to you and your car. However, whilst going too slow might not be as dangerous, it will be tiring for you and wearing on your vehicle.
In some cases the corrugations are so bad that you have no choice but to slow down to a crawl. However, in most cases where the road is otherwise safe and visibility is good, a speed of around 80kmh is perhaps the optimum; as the vehicle will tend to 'float" across the hollows, giving a smoother ride.
In every case, it is a question of sensible judgment. If in doubt, slow down.Your driving may be affected by your car’s suspension. Poor shock absorbers and over-inflated tyres will make you feel every bump!
When Off the Main Roads
If you're unsure of the ground ahead, especially if there is mud or water, get out and check.
Always keep your thumbs outside of, or on the edge of, the steering wheel as irregularities in the track can suddenly make the steering wheel turn with great force; which can cause a serious bruise or break to the thumbs etc.
Free wheeling hubs, which enable the 4WD front differential to be disengaged when driving, don't provide off-road capability automatically. Free wheeling hubs are designed to allow you to use the vehicle in 2WD; hence the vehicle suffers less wear to the differential and front running gear, and enjoys better fuel economy. So if your vehicle has manual hubs, you must lock them in and engage 4WD to get drive from the front as well as the rear wheels.
If you don't lock in the hubs and engage 4WD, the vehicle will remain in 2WD mode. This can be dangerous!
Speed and flotation are the keys to success whilst driving in the sand.
Having the correct tyre pressure is very important in sand. Generally 140kPa (20psi) is a good starting point. However, if you're heavily loaded, this may be too low and 175kPa (25psi) may be more appropriate.
If you're lightly loaded, or the vehicle is still bogging down, then 105kPa (15psi) may be the way to go for short distances.
This doesn't give you a wider "footprint", as opposed to a longer one, and makes driving in sand much easier. There is an increased risk of rolling the tyres off the rims as you reduce the pressure.
Our CEO tells us that he has had tyres down to 10psi to get out of very soft boggy sections. However, it is concerning to have them down that low; so don’t forget to increase the pressure again as soon as you can, or you'll ruin your tyres, or worse, have an accident.
It is recommended that you stick to existing wheel tracks, avoid sudden changes in direction, and tackle sand dunes head-on.
Never drive over the top of a sand dune, or any sort of hill, unless you know what is on the other side. Sometimes there are horrendous drop offs, big holes, and all sorts of obstacles that you will not be able to drive through safely.
When descending a dune avoid braking at all costs; keep the nose pointing as straight downhill as you can safely do; and don't travel too fast. It is also important that you don't go slow enough that the wheels stop.
If you do get stuck in sand, drive the vehicle backwards and forwards a little; building up a small stretch of hard-packed sand that you can move off from. Don't spin the wheels, or you'll only dig yourself in deeper.
Water crossings can be very dangerous. The greatest care must always be taken. Always check the crossing before you plunge in with the vehicle.
If you are not in crocodile country and the water crossing seems otherwise safe, it’s a good idea to walk through it first with appropriate footwear (such as boots).
Have a close look at it first in order to identify any potential dangers. If you cannot swim then we don’t suggest you enter a stream; unless you can be sure it is shallow and you will not get caught in a strong current. Even then, you may potentially slip and fall. Please ensure that you are very careful! There may be deep pools anywhere in murky water or clear streams.
If you cannot see that it is a safe depth, or if you are unsure of the surface underneath, take additional precautions, find an alternate crossing, or turn back.
A 4WD should be able to tackle a crossing of about 60cm deep without any problems or preparation. However, a soft sandy bottom or a strong current can change all that.
Before entering the water, you should spray all of the vehicles electrical components with a repellent such as WD40; loosen the fan belt, unless the fan has an auto clutch; and in deeper water, fit a canvas blind to the front of the vehicle. Ensure that you use waterproof tape to tape up air intake vents, doors etc.
You should drive into the water at a slow, steady pace (low second gear is generally best) and above all keep the motor running even if you have to stop. This may help to keep the water from getting into the engine via the exhaust system.
Once out of the water, you must allow your brakes to dry out. If you get stuck, check all of your oils (including diff oils) for contamination.
Some people prefer manual windows because they are safer in these situations; but they should be down when you start.
Finally, do not attempt to cross deep water in the dark - it just makes everything that much more difficult if visibility is reduced.
The key to driving in mud is to keep up speed and power. In deeper mud, low second or third is probably the most appropriate gearing. Keep up a steady pace and if possible keep out of wheel ruts.