In the last two months I have this problem happen twice. If i take a trip or go long distances with the truck, I come to a complete stop and go again, when I hit 10mph there is a loud 'clunk' from under the truck and it stops after that. It will keep doing it until I let the truck sit turned off for an hour or two. Then it disappeared and re appeared last night when I was driving on a trip. Same thing, let it sit for an hour or two and it stops. There was an error code thrown when this happened this last time, but I think it was un related, when they tried to pull the code at a dealership i found out there was an issue with my port, no power. Anyone know whats going on ? Truck has 114k miles on it.