Four-wheel drive basics

By the end of this topic you can

• You can choose between 2WD, 4WD high range and 4WD low range
• You can explain why part-time 4WD should not be used on dry sealed roads
• You can drive slowly and smoothly to keep traction
• You can check a water crossing before driving through
• You can describe safe basic recovery and the dangers of snatch straps

What you need to know and understand

• 4WD high range (4H) is for loose surfaces at normal off-road speeds, such as gravel or sand
• 4WD low range (4L) gives slow speed and extra pulling power for steep, rocky or very soft ground
• Many part-time 4WD systems can be damaged if left in 4WD on dry sealed roads
• 4WDs have a higher centre of gravity and can roll over more easily on slopes and sharp turns
• Lowering tyre pressures within the maker's guidance improves grip in sand, but you must reinflate before road driving
• Recover only from rated recovery points, never the tow ball
• Off-road vehicles on public roads and tracks still need registration and a licensed driver; rules for unregistered recreational vehicles vary by state

2WD, 4H and 4L: choosing the right mode

Check your owner's manual: some vehicles are full-time 4WD and some must be stopped or slowed before changing into low range. Engage the right mode before you reach the obstacle, not halfway up it.

• 2WD (where fitted): normal sealed roads, the everyday setting for part-time systems
• 4H: gravel, wet dirt roads and firm sand, at moderate speeds
• 4L: steep climbs and descents, rocks, deep sand or mud, where you need slow, controlled power
• Diff locks (if fitted): make wheels on an axle turn together for extreme ground; switch off once through

Keeping traction

Off-road, momentum and smoothness matter more than power. Wheel spin digs holes and damages tracks. Use gentle throttle, steady steering and a low gear. On steep descents, select low range first gear and let engine braking hold the speed, using the brake gently if needed.

Drive straight up and down hills, not across them, to reduce the risk of rollover. Before a creek crossing, stop and check the depth, current and bottom on foot if safe. If you would not walk it, do not drive it, and never cross fast-flowing or flooded water.

If you get stuck

A snatch strap stores huge energy. If a tow ball or weak point breaks, it can fly like a missile. Learn strap and winch recovery on a 4WD course before you ever use one.

1. Stop as soon as the wheels spin; more throttle digs you deeper
2. Get out, look at what is stopping you and clear sand or mud from around the wheels
3. Lower tyre pressures if in sand, within your vehicle's guidance, and try reversing out in your own tracks
4. Use recovery boards (traction boards) before reaching for a strap
5. If a strap or winch is needed, use rated recovery points on both vehicles and a dampener on the line
6. Keep everyone well clear, out of the line of the strap, during any recovery

Common mistakes

• Leaving part-time 4WD engaged on bitumen: switch back to 2WD on dry sealed roads
• Spinning the wheels: stop, look and reduce power instead
• Driving across a slope: go straight up or down to avoid a rollover
• Attaching a strap to the tow ball: only use rated recovery points
• Rushing into water: check depth and current first, and never cross floodwater

Test yourself: Four-wheel drive basics

Answer each question, then read the explanation. Questions come in a random order each time.