Off-Roading
Four Wheel Drive Concepts
Offroad Driving Techniques
   Basic driving skills
   Climbing steep slopes
   Descending steep slopes
   Traversing steep slopes
   Driving in mud
   Driving in sand
   Driving in snow
   Wading through water
Vehicle Recovery Techniques
Reference
Calculators
Off-Road Driving Techniques
Wading
Before You Start
Too fast, but it's a cool picture   Carefully inspect where you'll enter the water, and pay even more attention to where you're going to make your exit. There's nothing as frustrating as crossing a large expanse of water only to find the exit bank is too steep to get out! Be prepared - fit recovery ropes before entering the water, and consider a recovery strategy. Once connected, recovery ropes can be wound around the bumper or placed in the trunk. Ensure winching equipment is readily accessible.
Before you drive across water, check the water's depth and the surface beneath the water on foot first. Remember where you find holes and boulders. If the water is too deep or too fast-flowing to walk through, don't attempt the crossing.
Preparing the Vehicle for Wading
  • Fit wading plugs to the clutch and differential housings.
  • Remove the fan-belt to prevent water being driven into the engine compartment. If your vehicle is equipped with a viscous coupling fan, it will slow down by itself when water is encountered.
  • Where possible, connect recovery ropes and ensure other recovery equipment is accessible.
  • If the vehicle isn't diesel powered, spray the ignition system with a water repellent such as WD40 or Q20.
  • Place a cover across the radiator to minimize water entering the engine bay. This also prevents water being splashed over the ignition system.
Wind down your windows, and undo your safety belt. If something goes wrong you'll want to get out quickly.
When you're confident of your route through the water, engage low range second, and slowly enter the water. Don't enter with a splash which may cause the electrics to get wet. Keep the engine ticking over strongly at about 2000 rpm.
Good bow wave   Bad bow wave   Once in the water, aim to create a bow wave that gently pushes the water away from the front of the vehicle, without getting water into the engine bay. A plastic cover over the radiator may help. Avoid changing gear as this may cause water to enter the clutch housing. Back-pressure can also cause water to enter the exhaust system. Consider the two examples at left. The Jeep is fine. The Land Rover created a lot of turbulent water which caused the ignition system to get wet.
Once you've successfully crossed to the other side check the diff housing for water. Loosen the drain bolt on the differential housing and allow about 20ml to drain off. Because water is heavier than oil, it should clear the water from the housing. If the oil looks milky the entire housing needs to be flushed and the oil replaced.
DANGER! Serious injury or death can occur!
  • After driving through water remember that THE BRAKES WILL BE WET AND WILL NOT FUNCTION. Dry them out by driving while keeping the brake pedal slightly depressed. This causes the disks to warm up and dry out.
    Your vehicle can typically handle water that reaches the wheel hubs, or your knee. If the water is deeper than that, make sure you have a snorkel and extended differential housing breathers - when a hot diff housing comes into contact with water the temperature inside the housing will change quickly, also changing the air pressure. This will cause water to get sucked into the housing.
    Drowned Jeep   If it Goes Wrong
    In most cases a petrol engine will stall when water enters the cylinders. Don't try to restart it. Water doesn't compress in a cylinder the way air does. Forcing the engine to turn over will cause pistons, valves and the conrod to bend or break.
    Water-proofing Your 4x4
    • Fit a waterproof cover for the fuse box.
    • Fit a snorkel to the vehicle's air-intake.
    • Extend the diff housing breathers higher up the chassis of the vehicle. These are typically run up along the snorkel.