My 1999 Chrysler 300M's auto trans shifter to hard to move? ?

[Prince]

my 300m has an automatic trans. but the shifter is hard to move to D,N,R,P sometimes. i don't really know what to do. any suggestions? when it rains, the shifter moves freely and has no problem but when there is heat, i have problems moving the shifter.

 

[Kandi]

take it to a mechanic it or put some transmission fluid in it.