Im a complete noob. When do you use which?

 

Oh wow...

The easy answer is to check your owner's manual. 4HI is for most all off-road situations or any circumstance where there is traction is limited. Examples include beach sand, decent accumulation of snow on the roads, any trails, etc. 4LO is used very rarely by the average person. Situations where it would be necessary might include being stuck in mud, pulling another vehicle out of a hole, etc. I don't think I've used 4LO even once except to be sure of its functionality when I first bought the vehicle. Also, while you can shift on the fly to 4HI, you want to be completely stopped and in neutral before shifting to or from 4LO.

I guess an easier way to put it would be this: You know how on automatic transmissions on our trucks there's D(rive), 3, 2, and 1? Have you ever driven in 1 while in 2HI? You don't want to take it over 25MPH or so, and you really don't use it unless you're climbing a REALLY steep hill or any other situation that requires you to have a LOT of torque to get moving. The same is true for 4LO. You really don't want to use it unless necessary and you don't want to take it past about the same speed or too high of RPM's.

I'm sure there will be some replies from the other guys who 4-wheel a whole lot more than I do. I tried to be as general as possible while they might be able to provide more details for you.

 

Thanks, i haven't used either yet, cause i didnt know whic to use and didnt want to screw anything up. And i dont have an owners manual. My truck didnt come with one.