Yes, try to turn is a tight circle. Try first with it un-locked and then try to follow your same path with it locked.
There is a light on the dash that will tell you if it is engaged or not, but dont worry about that light, mine didnt work for 6 months, then the more I used the CDL the light started to work.
Once you get the shifter working use it once a month, just shift through all the gears and keep it working freely to prevent hassles in the future.

 

what would the difference be with it working and not? i would assume w/ it on the truck would "walk" or seem like it is pushing the inner most (of the turn)tire and w/ it off it would just follow or steer w/ no "pushing" motion. i get no difference w/ the lever in the left most "track" and w/ it in the right most "track" of the shifter selection. if the one side is broken maybe i'm not even engaging it correctly b/c it is broken also!.... i'll do a more thorough search and see if i am. thanx

 

I would say that it is broken.
Trying to turn in a tight circle with it engaged is next to immposible. It will "push" the outer wheel.