This vehicle is always in four wheel drive. The shift indicates what position the transfer case is in 2hi is for normal driving and 4lo would be in a slow speed situation like off road or pulling at a low speed. The N means neutral with the transfer case in neutral the wheels wont spin.
I will attach some information on the transfer case. If you still need help just reply, if not click ACCEPT when we are done.
Thanks. Just what I needed.