NHTSA Complaint #11715669 — 2017 FORD F-150

While I am driving in normal drive when my vehicle is in 6th gear cruising there is a shutter in the transmissionthat happens (like running over rumble strips)and only sixth gear. When I have 4 wheel drive locked in the transmission shutter happens in 3-6th gear and only happens at lower cruising rpms and trying to accelerate when I'm either using the pedal or cruise control. When I am in normal driving mode I have to leave 6th gear unselected so the rpms aren't too low to keep the transmission shutter from happening. Brought to the ford dealership and during the ride along with the tech he admitted he could feel it and could be 1 of 3 things the transmission, the torque converter or the torque converter control module. After picking my truck back up they said since I have no codes and they found a flaw in my rim. And that is what is causing the only sixth gear low rpm transmission shutter. And the shutter doesn't happen during higher rpms even at the same speeds. I have read up on this shutter and everyone was saying the same feeling in there f150s and was a transmission shutter. Don't want my transmission locking up at interstate speeds could cause losing control or causing an accident due to lock up