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   High & Low Range Gears
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   Vehicle Recovery Points
Offroad Driving Techniques
Vehicle Recovery Techniques
Ground clearance, simply put, refers to how much space you have between the lowest part of your vehicle (excluding the wheels and tyres) and the ground. This is typically measured as under-chassis clearance and under-axle clearance and, as can be seen in the figure below, under-axle clearance is substantially less than under-chassis clearance. Both have implications.
Under-Axle and Under-Chassis Clearance
Axle clearance implies how much space is between the ground and the lowest part of your axle, usually the differential housing. Knowing where the housing is situated (normally left or right of center) will help you avoid damaging the differential housing by driving it into rocks. Knowing how much axle-clearance you have will also help determine the depth of ruts your vehicle can successfully negotiate.
Approach, Break-Over and Departure Angles
The approach and departure angles are the maximum angle at which a vehicle can approach an obstacle, and depart from an obstacle, respectively. Most vehicles have a better approach angle because the tail overhang is longer.
Approach, break-over and depature angles
The ramp break-over angle is important as it determines when you're going to beach or "belly" your vehicle. This happens when you cross over a hump and the chassis rests on the top of the hump, leaving your front and back wheels spinning helplessly in the air. It follows that a short-wheelbase vehicle has a better break-over angle than a long-wheelbase vehicle.
Also remember that a tow-hook usually further reduces your departure angle. This is a point often overlooked and can catch you out when the tow hook digs in when reversing back down an incline. The flip-side is that if, say, your fuel tank is situated to the rear in an exposed position, it's preferable to damage a tow bar than a fuel tank. The same goes for bull or bush-bars, side-bars and so forth.
Increasing Ground Clearance
The only way to increase ground clearance on your vehicle is to fit bigger tyres. However, fitting really large tyres usually requires a suspension lift, body lift, wheel spacers, or a combination of these (see below).
Suspension lift with larger tyres