Do the ball joints on a 2007 dodge ram 1500 mega cab move up and down?

No, the ball joints on a 2007 Dodge Ram 1500 Mega Cab (or any other vehicle for that matter) do not move up and down in the way you might initially think. They allow for pivotal movement, meaning they rotate in a limited arc, primarily allowing for steering (the lower ball joints) and suspension articulation (both upper and lower). The up and down movement of the suspension is achieved by the entire knuckle/spindle assembly moving relative to the control arm, not by the ball joint itself moving vertically within its socket. The ball joint's movement is fundamentally rotational, not linear.