The ball tilt is used to pre-tension the WD bars or to adjust the number of chain links used to get a certain amount of WD bar tension.
The Dual Cam system depends on tension on the bars to do its job. If you do not have enough then sway can develop. We have a very good tutorial
here that explains how to set up your WD hitch. The second half of it is dedicated pretty much on setting up the Dual Cam sway system,
The Dual Cam is pretty finicky about being set up correctly so I would suggest you take a good look at it.
Good luck. :)
Barney