You always take a chance when you buy a second-hand car, but the signs of wear and tear are usually fairly obvious.
Family saloons are usually driven on public roads at speeds that cannot harm any parts. Buying a second-hand 4×4 is more risky. The vehicle may appear to be in a good condition, but there are many parts that may have suffered extra wear because of the way it has been used, or even abused. One consolation is that such vehicles are usually (but not always!) tougher than their family saloon counterparts.
It’s often instructive to talk to the previous owner, to find out how the vehicle has been used, but this is seldom possible. Nevertheless, a thorough inspection of the vehicle will give you some idea of what the owner has been up to.
If the clutch is not taking up smoothly and the gearbox is noisy, he has most likely done a lot of towing. This is not necessarily bad for the vehicle, unless the driver has been lugging the engine. “Lugging” refers to the popular practice of staying for too long in a high gear, especially when going uphill, instead of changing down to a lower gear. The engine and gearbox prefer higher revs than the greater loads that accompany lugging.
Examine the underside and body for signs of rust. Pay special attention to the wheels, chassis members and suspension parts. Rust often shows up first around the bottom of the doors and tailgates and other places where water can gather. If the rust is severe the vehicle has probably been used for towing an ocean-going boat, and launching it from a slope. Salt water is extremely corrosive, and rust is difficult to combat. Such a vehicle may not be worth buying.
You should also examine the underside for mechanical damage. A good 4×4 usually has a separate chassis, and that’s the best place to start with your inspection. Scrapes and dents will give you good idea of how the vehicle has been used. Even a welded-up floor-pan will have a story to tell. Cracked chassis outriggers will tell you the vehicle has been overloaded or driven hard on dirt roads. Dents in the cross-members and scratches on low points are evidence of serious rock climbing. Such a vehicle has obviously spent a lot of time off road.
The interior, and especially the seats, will also show tell-tale signs of hard usage. Lift the carpets and look for signs of damp and rust. If the inside rust is severe, the vehicle may have been used for wading and has not been dried out regularly.
A good 4×4 has at least a gearbox, three differentials, six universal joints, a steering box and a transfer box, as well as other components that must suffer if water can force its way inside.
Oil contaminated with water has a milky-brown colour, but unfortunately very few of these parts can be opened up to allow inspection of the contents. In such cases, the condition of the rest of the car is your only guide to the way it has been looked after.
Park the car on a level surface, and look for signs of sagging springs. Use a tape measure if you have to. Examine the bump stops. They will tell you if the springs are soft or the shock absorbers are not working. The latter should be dry and show no signs of mechanical damage. Heavy front-mounted winches may cause unnatural sagging of the front springs.
The best test for shock absorbers is to drive the vehicle over a section of uphill corrugations. Under power, a faulty shock absorber will cause the vehicle to leap around and refuse to run straight. Shock absorber test machines can seldom be trusted. The operator is usually trying to sell you new “shocks”!
Be particularly suspicious of vehicles that have been modified, and keep in mind that insurance companies are very wary of them. Modified suspension is often an improvement but engine modifications usually reduce the engine’s chances of surviving for a long time.
Engine transplants often result in problems or disadvantages that the first owner could live with, especially if he made the changes himself, but any subsequent owner is less likely to put up with them.
The problems that usually occur are noise and vibration, unsuitable gear ratios, heavy fuel consumption, a reduction in clutch plate life, overheating and inadequate braking ability.
An amateurish wiring system may be a fire risk. Also, check that the engine number matches the one on the licence form.
Most modern engines are tough, but they can generally be ranked as follows:
Naturally aspirated diesel engines tend to last the longest. Toyota is the only manufacturer that still sells such engines in SA – in certain Land Cruiser models.
Naturally aspirated petrol engines are also capable of lasting a long time because they can cope better with infrequent or bad servicing.
Super- or turbo-charged petrol or diesel engines must be serviced correctly at the recommended intervals. Even then they will “bite you” if they are not driven with some degree of feeling for the machinery. – Jake Venter