My 2010, Hemi, Crew Cab has a growling noise under certain conditions, coming from the engine area, through front floorboard, after the last shift, I assume torque converter lockup, in 5th gear only at speeds of 43 - 55 mph. This noise is heard with very slight throttle without downshifting. If it downshifts the sound goes away. This sound is heard in normal drive or with tow haul mode engaged. It happens only occassionally without towing, but very often with my boat being towed. Had to take my boat to the dealer and drive them so they could hear it. Very loud towing my boat. Service manager said it is the exhaust making a resonating sound and says other trucks do it also. Did not have another truck on lot to drive. Does anyone else have this sound on their truck or any ideas of what it might be? Dealer has removed all heat shields on exhaust and reinstalled, but noise is still the same. It has had this noise since new. Today was the 4th time to the dealer and I still have the problem. Sorry for the long post. Thanks to all who might help.