Well According to the Tech at the dealership, he said that it looks like someone didn't tighten the bolts on the Harmonic Balancer the last time it was worked on. I told him that no one has ever worked on the truck and the last thing to touch the Balancer was the robot at the factory. These are the notes on the Ticket when it was returned to me.
Verified customer concern of the Harmonic Balancer broke off. Also found the balancer bolts broke off in the crankshaft and the crank broke out of the side of those holes. The balancer looks like it bounced around when it came off because multiple other parts were damaged in the process. The water pump, fan support, fan pulley, upper idler, tensioner, belt, crank sensor, and the harmonic balancer itself was all damaged. The fan support bolts were broke off in the block too. Opened Star case and was advised to take pictures of the valve train. Was also advised to pull the pan for a main and road inspection. Star also wanted the head pulled for inspection. Pulled the head, removed removed the pan and sent in all of the pictures. Once the new engine arrived, pulled the old block and moved all of the parts over including replacing the damaged parts. Needed to repair a crank sensor harness and the fan shrouds. Reassembled the new engine in the truck and set the cab back on. Found the fan clutch harness in need of repair too. After all repairs, filled with new fluids and recharged the AC. Bled the brakes and adjusted the parking brake. Cleared the related codes and road tested. At time tested, the truck drives like a comparable vehicle. "These are the Techs notes word for word."
I will say this, The truck ran great. It started losing power at 70mph. Warning lights came on. "Service Crank Sensor", "Service Traction Control System", "Perform Service", "Service DEF System" all within about 20 seconds. Stopped on the side of the road, Very Rough Idle. Revved Engine and things smoothed out. Pulled back onto the Interstate and at about 60mph heard a loud "CLUNK" Engine immediately over heated, Lost brakes and steering. Had it towed to the shop.
Hope this helps