I would like to know how to use the 4H? I took my truck to a perfect spot (lots of mud) and was not use if the 4H would kick in by itself and therefore used the 4 L just in case. Can someone please explain to me when will the trucks' front wheelsstart working when on 4H?The last thing I would like to do is mess up my transmission just because I don't know how to use it. Thank you in advance.


Sincerely,
Fabian
Brownsville

 

Sorry about the gramatical mistakes!!! I meant to say:
sure not use in second line
[&:]

 

What year Discovery do you have?

These trucks have permanent 4 wheel drive, which means you are always in 4H by default. If your truck has a locking center differential, your transfer case shift lever will have 4 positions: 4L and 4L locked, + 4H and 4H locked. Here is my rule of thumb, and others will have their own preferences.

4H: all around driving, including in snow and most off road
4H locked: Below 30 MPH when I need extra grip like going up a snowy or muddy hill that's not very steep.
4L: Below 10 MPH off road, when I'm going up or downa steep or very steep hill that has a firm, hard dirt or embedded rock surface.
4L locked: Below 10 MPH off road when I'm going up or down a steep or very steep hill that has a very loose or muddy surface, or through deep sand and mud bogs.

Dave