Oil Pump and Truss Frame
In the following close-up you can see an oil pump on the lower left and a fuel pump on the lower right. Both are driven directly by the crank shaft. A small motor is attached to the left side of top belt, and it is driving the water pump. The large black hoses heading toward the back carry water for the radiator to and from the engine's water pump.
In the "bed" of the truck you can see the vehicle's substantial truss frame: