What part of the kingpin should the locking jaws close around?

The correct focus of the locking jaws is on the shank of the kingpin. The shank is the cylindrical portion of the kingpin that provides the necessary stability for the coupling between the truck and trailer. When the locking jaws close around the shank, they secure the trailer to the truck, ensuring safe towing during transport.

Understanding this mechanism is crucial for vehicle operators and anyone in logistics or transportation, as proper coupling secures loads and prevents accidents. The other parts of the kingpin, such as the head, base, and tip, also play roles in its overall function, but it's the shank that directly interfaces with the locking mechanism to maintain a secure connection.