Note: This is a very very very brief explanation regarding the differences.
- Part-time 4wd is selectable from H2 to H4 (see above photo).
- When in H4, both axles are driven at the same speed which causes axle wind-up when cornering.
- When travelling on an unsealed road surface in H4, axle wind-up is dissipated through road wheel slip due to travel on a low traction surface.
- Therefore, H2 must be used travelling on a sealed road surface to avoid axle wind up damage.
- Full-time 4wd has a centre differential (CD) to prevent axle wind-up on sealed roads.
- The CD allows the front and rear axle to be driven at different speeds when cornering.
- The CD has a negative effect when travelling on unsealed roads as it tends to want to send all of the drive out of the wheel which has the least resistance.
- Some full-time 4wds have a manually locking CD (see above photo) while others have an automatic system which engages as and when needed.