If you watch a live axle 4WD cross bumpy ground, you might notice that the wheel travel works diagonally, if the right, rear wheel is up, then the left, front wheel will also be up.

In between your two wheels is the differential. It always delivers power to the wheel with the least load. So the wheel with the least load (traction), receives the power, and just spins uselessly, while the other wheel, receives no power.

The result is a complete loss of forward motion.

Combine this with the fact that the axles work diagonally and the usual situation is a stuck car with two fully crossed up axles and two opposite wheels spinning away uselessly.

You should always be reading the ground ahead and carefully guide your wheels over obstacles in a way to use as little wheel travel as possible.

Sometimes looking carefully at the ground actually involves getting out of the vehicle.

Notice the “crossed up” wheels in the photos above. Once you’ve crossed up too much, you’ll stop going forward.

SRODRV001B/04 USE THE FEATURES OF A 4WD TO DRIVE A VARIETY OF TERRAIN TYPES

PERFORMANCE CRITERIA 04f