Well some times they stick and some times they are bound up. When they are bound up lift with your jack you should see the hitch relax. If it does not relax drop it till it relaxes. If it is stuck you will still see it relax. then bang it with a hammer and it should let go. You should never have to move the truck while the jack is down. Well not very much at least. When you see it relax get into your truck release the hand brake or take it out of park and let the truck settle. that should be all there is to that. If you need to gorilla it something is wrong. OH keep lots of grease on the ball all the time.
