Put it up on jackstands and put the jeep in Park. Loosen the trunnion bolt at the bottom of the upper shift rod so that the bell crank and the shift rods will slide freely.
When you adjust it, there should not be any slack left. Tighten it up and try cranking it in Park and Neutrel just to make sure it all lined up right.
Oh yeah, while you still have it up on jack stands, when it is adjusted, the drive shaft should be locked when you have it in Park.
Hope this helps. I only know this because I am having some issues myself and have been reading on how everything works.