Having a center differential will allow you to use 4wd on the street without binding things up. If you dont have a center diff and you drive on the street and make sharp turns, you can bind up your drivetrain and do some damage.

 

i think im gettin it...sorry guys.. so say its snowin and i want 4wd for the street i should put it in 4wd high and then press the button, but if im offroading or something just put it in 4wd h or low is this correct?

 

I don't think you would need to move the shifter, just simply push the button

 

yea i know its in high gear now but to engage you push the button on the shifter and then if im on the road and making turns and stuff i should also press the center diff lock button