4WD-INSIDE AND OUT AND 4WD TECHNIQUES:
An all wheel drive/4X4 might get you to most of the places on the planet as long as there is ground under its tires.
The present generation of 4X4's available are endowed with good off-road ability, but for going to places where no wheels have been before, an off the shelf 4X4 will have to be given a once over. Modifications to the Engine and Drive train, suspension, addition of winch, extra driving lights, rollover protection, long-range fuel tanks, installation of communication and or navigational equipment (HF / VHF radio, GPS / SATCOMM) and to support all this a dual battery electrical system will have to be considered.
However no matter how capable the machine is, the person at the 'wheel' is more important. If one is planing an extreme adventure, joining a 4WD owners club and/or taking a specialized 4 wheel-driving course is advised. The modern 4X4 is a complex piece of engineering and therefore the need to be able to handle all the equipment and the need for sound technical knowledge cannot be ignored.
The first step would naturally be to get to know your equipment, its strong points and its limitations.
A SUV/truck equipped with a winch can be recovered without outside help, using a stationary object in the form of a tree, a buried log or crowbar, etc. If there is no winch, the bogged vehicle can be pulled out with the aid of a cable one end of which must be secured to a stationary object and the other one, to the wheel disc. A slip-ping or bogged automobile can be recovered by another automobile using a flexible or rigid towing device (a rope or a pole) coupled to the towing hooks or the frame. Whatever the method of recovery, first tension the rope/cable then pull out the bogged vehicle smoothly, without jerks. The country roads intended for animal/horse-drawn vehicles, as a rule, are of a poor quality. However, sometimes earth roads are made for automobiles, too. In such a case they are graded and provided with water drain ditches. Usually, earth roads are characterized by a multitude of turns and surface irregularities. 'When wet, these roads become difficult for driving. The wheels dig deep into the slushy ground; the resistance to rolling grows so high that further movement may be rendered altogether impossible. If the automobile has to be stopped, you had better do it on a relatively higher ground, where it is not so wet. Do not drive fast on wet earth roads, do not make steep and sharp turns and avoid halting on an uphill slope. Accelerating and braking the vehicle smoothly, without jerks, permits the Driver to avoid slipping.
A dry earth road may present unexpected obstacles, there-fore the driver should select such a speed at which he would be able to slow down the automobile in time and negotiate the obstacle. Difficult stretches, deep ruts, pits, ditches, sticky or loose soil, snowdrifts, and the like characterize the earth roads.
For crossing a hole, approach it at a low speed, apply the brake, and downshift. When the front wheels descend into the pit, throttle up the engine. As soon as the front wheels have cleared the hole, brake the automobile again so that the rear wheels would cross the hole with equal smoothness. Shallow ditches are crossed in the same manner. The obstacles standing out above the road level must be negotiated as follows: while approaching a hillock, slow down the vehicle, downshift and throttle up the engine as the wheels have climbed the hillock, re-lease the clutch and allow the wheels to roll down smoothly; repeat with the rear wheels. A ditch with steep walls should be examined, the sharp edges should be cut off, throwing the earth down into the ditch. If this proves insufficient, fill the ditch with logs, twigs, stones, and other improvised materials.
Bridges on country roads are not always provided with signs stating their load-carrying capacity. In such a case, the driver must use his judgment and estimate the strength of the bridge by the thickness of the piles, top plates, main girders and flooring. Apart from the thickness of individual bridge components, their condition should also be examined (look for cracks, rotting, and other defects). If the flooring looks unreliable, laying two thick planks coinciding with the track width of the vehicle can reinforce it. Stopping and overtaking of vehicles over the opposite-traffic lane is as a rule not permitted on bridges of any kind.
During a fog, snow/and or rain and on a dusty road, when the visibility of the road ahead becomes very poor, drive at a slow speed to be able to spot danger in time and take adequate measures. The rainwater fills the potholes on the road and the vehicle must be slowed down so as not to get into these holes. The brake shoes become wet during the rain, which decreases the braking efficiency. To dry the shoes, drive a short distance with the brakes lightly applied; the brake shoes will become heated and the moisture will evaporate. On dusty roads, it is necessary to fall well behind the preceding vehicle to have enough time to emerge from the dusty stretch at a safe distance from this vehicle. As the visibility gets worse owing to fog, snow or rain one must switch on the marker lights; in case of a thick fog, turn on the traffic lights or fog lamps. While halting on the road, be sure to switch on the marker lights though a better practice is to move off the road.
While crossing an ice-covered river, there must be no people in the automobile save the driver, and the automobile must be driven on ice quietly, at a speed of 15-20 km/hr (10-12 mph).
If several automobiles are crossing the ice at a time, the minimum intervals between them must be 25-35 m.
While loading your family/gear/kit, first load the SUV/truck, then the trailer.
As far as possible, avoid halting on sticky and loose sections of earth roads. In such places, it is difficult to start the truck-trailer from rest, the driving wheels of the SUV/truck may dig into the ground and it will be impossible to get on without outside help.
Finally a few words on turbo charging. An Exhaust driven turbo charger will increase the performance envelope of the SUV/truck but this may not be the best for towing duties. Turbo charging usually kicks in the middle to top end of the rev range while towing demands low-end torque which is best derived from cubic capacity i.e., cubic inches.
Under difficult road conditions the automobile engine and other mechanical elements are subjected to heavy loads. On difficult sections of the road it is necessary to select lower gears; however, pro-longed driving in low gear may overheat the engine, there-fore the water temperature gauge must be watched and, when necessary, the engine must be stopped and allowed to cool down. Jerks and abusive engagement of the clutch on diffi-cult sections of the road overstrain the drive train components and may even lead to their premature failure. If the automobile is slipping in a soft loose soil, its wheels dig deeper and deeper into the ground and it gets mired; special measures must be taken to prevent the automobile from sinking so deep that its axles will rest on the ground. To recover a bogged vehicle, lift its wheels with a jack or a lever and put planks, stones, brushwood, poles, timber bars, crushed stone or other improvised materials under the wheels. Pass-ability of the vehicle can be increased by the use of link or track type of anti-skid chains, wire-mesh mats etc.
On steep uphill slopes do not persist in driving in high gear until the speed drops low, but shift over to a lower gear in due time. However, an excessive drop of speed will call for a lower gear and, eventually, will result in a loss of time and increased consumption of fuel On a gentle and short downhill slope it is allowed to coast; on the contrary, on a long and steep downhill gradient, all the more so if the road is slippery, use the gear which you would use while climbing the same gradient.
Driving in mountains is complicated by steep and long uphill and downhill grades, by many sharp turns with obstructed view and, quite often, by a relatively small width of the roads. At an altitude, the atmospheric pressure drops, which affects considerably the engine power and the functioning of the air brakes. At high altitudes (above 2,000-2,500 m above sea level) the driver's fatigue increases due to lack of oxygen. Before going into the mountains, be especially careful in checking the technical condition of the automobile, the steering and brakes in particular. The vehicle should be fitted with anti-creep devices preventing it from rolling down if it has been halted on a slope. Before climbing an uphill grade, select a gear that will enable the vehicle to negotiate it without gear shifting. Anti-skid chains should prevent slipping and creeping down of the automobile on slippery mountainous roads. Do not start climbing a steep uphill gradient until the preceding vehicle has reached the crest of the hill. In case of emergency, when it becomes necessary to stop on a slope, the vehicle must be securely braked and special chocks placed under the wheels. If chocks are not avail-able, throw in the reverse gear and bring the vehicle to rest against a stationary object, e.g., a large stone. While going, downhill, do not overtake other vehicles; braking must be assisted by the engine.
Adhesion of wheels to sand, particularly dry sand is not great; besides, the wheels cut deeply into the sand. The automobile must be driven at a uniform speed, in a gear, which will ensure movement without gear shifting. If the wheels start slipping, clear the paths ahead of the front and rear wheels and starts the automobile smoothly from rest in a low gear.
Short stretches of muddy road must be negotiated on the go, without shifting the gears. The sections flooded with water should be inspected in advance to avoid getting into a deep pit or hitting a stone covered with water. On the road covered with a deep layer of thick mud the vehicle must be driven in a low gear at a constant engine speed; if there is a shallow rut, it is advisable to direct the wheels over this rut. An automobile bogged down in mud should be moved forward or backward, using anti-skidding devices.
To cross a water obstacle, first the ford must be examined. The approaches to the ford must be gently sloping and the bottom of the river must be sufficiently hard to prevent slipping of wheels. The depth of water should guarantee that water would not get into the carburetor and ignition distributor. The fording depth for the passenger cars and trucks must not exceed 0.5 m and 0.7-0.8 m, respectively. The fording route must be marked with flags or stakes. Before crossing a water obstacle, close the radiator blind shutters or place a special shield on the radiator, remove the fan belt, and transfer the storage battery into the cab.
Rivers with a strong stream should be crossed at an angle, moving downstream. Approach the water slowly, in a .low gear, then cross it quickly without stopping. Having crossed a river, allow the water to drip down, put the re-moved parts and units back in position, and resume motion.
Be sure to examine the ice thoroughly before attempting to drive across it. Particular attention should be given to the ice near the riverbanks.
Negotiate small snowdrifts at a high speed-Deep snow must be negotiated in a low gear at a low speed. It is better to move along ruts, because packed snow offers lower resistance to movement. A slipping automobile should be backed for 2 or 3 m and then smoothly driven forward. If repeated attempts to traverse a snowy section prove fruitless, it is necessary to clear off the snow.
Driving a SUV/truck with a trailer in tow is somewhat more difficult than that of a single automobile in view of their larger length, weight, turning radius and braking distance. One must always be perfectly certain that the coupling is perfectly reliable and must, therefore, inspect it personally. The SUV/truck-trailer must be started from rest smoothly and accelerated gradually. While in motion, the trains must not be sharply accelerated, decelerated, or abruptly braked. The gearshifts must be quick. While climbing an uphill gradient, downshift to such a gear that will enable the vehicle to reach the crest without gear shifting. If you have to stop, select a horizontal and convenient place for stopping your train. On downhill grades, drive at a low speed and brake with the engine. While cornering, bear in mind that the turning radius of the trailer is smaller than that of the towing SUV/truck so that the trailer wheels may roll off the road. While passing the oncoming vehicles, reduce the speed, but tension the trailer coupling so as to prevent the trailer from overrunning the truck and moving sidewise. Most dangerous is the side rolling of the trailer towards the oncoming vehicle. During tricky maneuvers and backing, the SUV/truck and trailer may jack-knife and break the coupling.
