When inspecting the fifth wheel gap, what should you verify?

When inspecting the fifth wheel gap, it is essential to verify that the locking jaws are fully closed around the kingpin. This is a critical safety measure because if the locking jaws do not securely grip the kingpin, it could lead to a detachment of the trailer from the towing vehicle while in motion, creating a dangerous situation on the road. A proper lock ensures that there is no movement between the trailer and the vehicle, which is vital for safe towing.

The alignment of the trailer with the towing vehicle, while important for hook-up safety, is secondary in the context of the locking mechanism's functionality. Verifying that the air brakes are released is also significant, but it pertains more to the operational readiness of the vehicle rather than the structural integrity of the connection between the trailer and towing vehicle. Lastly, ensuring that the trailer lights are functioning is crucial for visibility and signaling but does not impact the mechanical coupling that the fifth wheel inspection focuses on. Thus, confirming the locking jaws' full closure is the most critical action when inspecting the fifth wheel gap.