 CHOOSING THE RIGHT VEHICLE Most people will already have a vehicle in mind when preparing an expedition. There is no point in getting into a Land-Rover versus Toyota type argument here. Every make and model of vehicle will have its strengths and weaknesses. If you’re familiar with a particular vehicle and are confident about maintaining it and fixing it yourself that will get you a lot further than trying to use an unfamiliar vehicle just because someone else recommended it. Your main consideration should be how simple it is to keep going and get you to your destination. All the electric trickery fitted to modern 4x4s are no use to anyone if it breaks down and you cannot fix them. Vehicles with Engine Management ECU systems should only be used as a last resort and no amount of cup holders and leather upholstery is going to help you fix a broken half shaft. Usually the more basic the vehicle the better, the only draw back is that this usually means an older vehicle. Your choice could also be influenced by your destination. Many African countries have vast quantities of old Series III Land-Rovers ‘lying around’ so if you go in a Land-Rover you are pretty certain to find spares and more importantly someone with experience of working on them. BASIC These few points are things for you to consider: CLASS OF TERRAIN Here we break up the various terrain you will encounter into FIVE classes: 1 – Good road, no off-road, 4x4 capability not really required CLASS OF VEHICLE Small Recreational Vehicle: These are squarely aimed at the ‘fun’ market. The perform well on urban roads and admirably on dirt tracks but not a real consideration for Difficult Terrain with their very low ground clearance. Can still be used for shorter getaways if you tow a trailer to carry all the equipment. Short Wheelbase These can give you as much power as a larger LWB vehicle, can have much better agility off-road and better approach and departure angles. The only down side is the relatively small load space. Medium sized 4x4 Firmly placed in the ‘serious’ off-roader category but even here the capabilities of different models varies wildly. A Discovery is a true ‘go-anywhere’ vehicle whereas a Cherokee of the same size will not have the same capabilities. Full-Sized 4x4 Purpose built off-road vcehicles with excellent abilities and huge load carrying capacities. Dual Cab Pick-Ups Some of these models are primarily commercial pick-ups that have had 4x4 capability added later. They will have good off-road capability and load space but are not really for extended expeditions. Heavyweights These will definitely go anywhere and carry massive loads along the way. But the downside is also their size and weight. They won’t be any good in tight areas or soft ground like sand or mud. You will also find that they are too wide for many bridges and tracks. PETROL OR DIESEL You might think that this consideration is just down to personal choice but you would be seriously wrong. Many areas, like Eastern Africa do not have reliable supplies of Petrol. In other areas the petrol on offer will be of such a low quality that your modern 4x4 that’s been used to high grade unleaded fuel will just not cope well at all. Other Areas like North America have better supplies of petrol than diesel. A diesel will have a huge amount of torque at low revs for serious off road work but the downside is that they will be a lot slower than similar petrol models. When things break –and you can be pretty sure that they will – it is probably going to be easier to fix, permanently or temporarily, a petrol unit. If a diesel fuel pump or intercooler gives up you have a serious problem on your hands with no spares available. Whereas a Petrol engine can usually be made to limp home after all but the most serious of problems. SUSPENSION Once you’ve figured out all the other variables we spoke of in the previous sections you might think this one is redundant BUT there are some very important considerations to make when looking at vehicles with leaf springs as opposed to coil springs. Similar to the question about petrol v diesel it can be down to personal choice but there are other factors to take into account. Both Leaf and Coil suspension are able to cope well with heavy terrain. Coils will give a smoother passenger ride and coupled with independent axles can give more articulation to stabilise the vehicle and thus making it easier to drive. The downside to this is that a Coil system can insulate the driver to conditions of the road and can tempt you to drive faster or take more risks. If you had leaf springs you will know exactly what’s going on under you and will probably slow down acordingly. Leaf springs are more prone to breaking than coils and although they can be ‘fixed’ fairly easily you should consider strengthening the whole system beforehand. You can add extra leaves to the spring to give strength, at the expense of comfort. You can add a ‘Ball Assister" between the axle and the chassis to act as extra dampening. This must be fitted carefully as they do have a tendency to slip out of place. Some of these systems also utilise an inflatable ball that can be inflated or deflated to accommodate differing loads and terrain. If a Leaf should break it is fairly easy to fix by welding – most industrial areas or mines will have this equipment. The best fix is not to just weld across the break in a straight line but to use a ‘Diamond’ joint. If you are preparing for a long trip you can pre-prepare these diamond bits and take them with you as spares. Similarly you could take extra leaves to replace broken ones. Shock Absorbers. Although you could drive a 4x4 vehicle fairly easily with broken or missing shock absorbers or dampers it is important to know exactly what their role is in your suspension set up. They do not alter the load carrying capacity or strengthen the suspension in any way, and on their own they cannot alter the ride height without similarly altering your springs. Shock Absorbers simply absorb some of the shock from the road and eliminate some of the rapid up-and-down movement of the body as well as the controlling body roll. All of this contributes to better stability and an easier ride. The magazines are filled with adverts for different types of Shocks all promising different effects and conditions. Basically there are three basic types; oil filled, gas filled and a combination oil & gas. It is recommended that you ignore any fancy promises and models that can be inflated or deflated, these are designed for short off-road competitions and ‘day trips’. On a long expedition your safest bet is to just stick to the same ones that your vehicle was originally fitted with or at least a similar version from another manufacturer. Similar to your choice of springs, choosing shocks that offer a better ride can act to insulate you to the conditions of the road and allow you to forget what your suspension is having to cope with. You should always carry at least one front and one rear spare shock absorber but you may find on very long trips that you use these and still need to find more, it will be far easier to get ‘standard’ shocks. TIP: an basic protection used my many expedition drivers is to cover the bottom of shocks with a short length of PVC tube to protect them from stone and terrain damage. TYRES Sometimes choosing a tyre can take longer than any other aspect of vehicle preparation. Pretty well all the best known brands produce a wide range of very good quality tyre but choosing which to go for can cause many headaches. After planning you trip you will need to determine the what type of terrain you are likely to encounter. Tyres designed to withstand rocky terrain will not be very good in sand or mud and vice versa. Soft sidewalls are ideal for sand allowing you to deflate to give a larger footprint but these will be torn to shreads over sharp rocks. Cross-Ply Tyres – These tend to run a lot hotter than radials so make sure you constantly check their pressure. A simple – if basic – way to check you pressure is to touch the tyre after a long days driving. If the tyre is hot it is probably under inflated, if it remains cold it could be over inflated. Always check with a reliable guage!. These are constructed from harder rubber and the layout of the ply across the width of the tyre gives very strong sidewalls – essential for rocks – NEVER consider over inflating a radial tyre to give better protection against rocks. This will NOT strengthen your sidewalls it will just make them explode if you get a puncture! Radial tyres are made from much softer rubber which can be slowly ‘eaten’ by rocky surfaces as tiny bits are gouged out as you drive along. The rubber surface of the tyre will quickly decrease leaving you running on the steel foundation. In sand it is much better to have tyres with deep channels or grooves rather than aggressive lugs this way you can ‘float’ on the surface. The exact opposite is required for muddy conditions where you need the extra aggression to enable you to get a good grip and sometimes dig down to firmer conditions underneath. You could end up trying to find a decent compromise that will cope adequately in all conditions. But this will mean you MUST adapt your driving style accordingly and be prepared to inflate or deflate the tyre pressure as you encounter different terrain. Whether or not to use inner tubes with your tyres can also come down to personal choice and sometimes a little bit of ‘myths and legends’ A good quality radial tyre correctly fitted and deflated to a very low pressure in sand should still not separate from the rim as long as you drive slowly and sensibly. ALWAYS follow the manufacturers advice.
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