No hanger bearing on your truck, Haifisch, your driveshafts are too short. Plenty of places for metal-on-metal rubbing sounds, from the hood not having the leather strips in front so it rests on the metal grille, engine side panels not having the rubber stops and chafing and rattling as a result, to fenders against steps, and probably several more places. Do the cab floor covers have all the fasteners in them? Lovely rattles come from those!
When the truck was designed, the presence of a human in it was an unfortunate distraction from the mission, so this need was accommodated without fuss, such as sound proofing, ventilation, heating, comfort or other weeny kid items.
No harm in checking U-joints. When you are under there, pay close attention to the fasteners of the "shorty" driveshaft between tranny and transfer case; they have a nasty habit of coming loose.