I accidentally left my 2008 dually in 4wd and drove 280 miles at freeway speeds. I can’t explain how I didn’t feel it buck when I turned, but I guess I am an idiot. Anyway, the Service 4wd message is on, but the transfer case works in all gears, and the front driveshaft turns but I have no power at the front wheels. I replaced the actuator motor on the front differential (factory GM part) and it still doesn’t work. I have done lots of searching on here, and I cleaned the ground wires under the drivers side, and I did the 4wd reset trick by holding the switch in neutral for 45 seconds with the key in the accessory position and the truck in neutral. The reset cleared the message for a while, but it still doesn’t work. Could I have broke the fork or something inside the front differential?