Please help with SUBMARINER!!!

[rolex_DateJust]

Hello guys, my "U" serial sub is acting pretty strange lately and don't know if it's because it's obvious something is loose in the movement or I need to do  maintenance already! When I unscrew the crown, I put it on the first click (date change) and when I turn it, the date doesn't change... When I pull it out to the last click (time change) it changes the time and if I keep on going through 24hrs, the date will change with it! When I shake the hell out of the watch, I put it back to the first click and THEN the date changes but gets stuck after a little bit of turning and doesn't turn anymore! I'm freaking out lol! Please help!!