Ok, I thought it was. This problem is most likely the lock up torque converter unlocking and re locking at cruise speeds. This is usually caused by electrical noise coming from loose battery cables, bad batteries, loose grounds, a noisy alternator or a failing APPS (Accelerator Pedal Position Sensor). This is a known problem on these trucks and your Dodge dealer is well aware of this. The first thing I would do is to have both batteries tested and replaced if needed. (if one tests good, and the other one bad, replace both of them). Make sure cables are clean and tight. If this does not help, then have the dealer verify that the software in the PCM (engine computer) is up to date, and then have them check and repair for electrical noise in the system.

I hope this information helps, and let me know if you need further assistance with this.

Chris