04 6.0, got oil in the coolant. Truck has had head gaskets replaced, ARP studs. Truck runs perfect, zero smoke, no other indications. Son was in an accident several months ago, front end damage. Of course initially I thought blown head gasket but it just doesn’t make sense. We don’t tow with it and the truck is treated very good. Got to thinking maybe transmission cooler was damaged in the accident and checked transmission fluid and it’s low. Would this make sense? Like I said, truck starts right up and runs fine, no other indications.