hi all - newbie here.. bought a 99 pathfinder SE. and unfortunately, it didnt come with an owners' manual so i started playing around with the shift procedure.. i was reading the card on the front visor.. i have the automatic.. so i put the car in Neutral then pushed the stick and pulled into 4L.. then i pushed the stick again to put it back to 2H and the thing grinded for about 2-3 seconds.. damn i dont know if i caused any problems to the transmission, please someone tell me otherwise..

car seems fine but i feel so guilty.. anyone know how to use this thing properly.. please help!!
another thing.. if the car is on 4L , should the selector lever be on N or D ?? this thing is confusing.. if someone could shed some light, i'd greatly appreaciate it. thanks :help