Have a shutter when i put it n reverse. It acts like it dont wanna go onto gear on 2005 Jeep Liberty

i started it this morning& gave it a lil gas & it just reved. I put it back in park then tried it againg. This time it went. It seems to shift hard sometimes. I got to work and was backing into the parking place& it shuttered bad while backing up

Asked by for the 2005 Jeep Liberty