There are 5 positions on the Center Diff Lock Lever.
- Neutral, which runs left to right across the middle;
- 4 high unlocked, which is back and to the right;
- 4 high locked, which is back and to the left;
- 4 low unlocked, which is forward and to the right; and
- 4 low locked, which is forward and to the left.
Locking the center differential ensures that engine power is distributed equally between the front and rear axles.
You can engage or disengage the center diff lock at any time and in any gear, which can help your chances of having power at a wheel that needs it in slippery conditions. However, you should only engage 4 Low from 4 high -- or vice versa -- while in neutral and rolling
very slowly (your gears will clash otherwise, and it's not pretty).
This is a basic overview but it should help you understand the center diff lock feature. Others with more specific technical know-how might chime in on details....
Hope this helps,
Andy