While driving down road at around 60mph 6.2L engine started to make loud knocking noise and shaking violently while loosing all power. Truck had 79,797 miles on it at the time with all oil changes and service done at GM dealership. After having GM dealership diagnose truck, it was determined to have a spun rod bearing, causing multiple other engine components to fail. Truck was not under factory warranty and was quoted $12,200 to replace. There were no warning lights or any known issues until this incident.