After coupling, where should the fifth wheel locking jaws be closed?

• A.Around the head of the kingpin only
• B.Around the shank of the kingpin, not around its head
• C.On the trailer apron plate, beside the kingpin
• D.They do not need to close if the safety latch is down

Why

The jaws are designed to grip the narrower shank of the kingpin, with the head keeping the pin from pulling out. Jaws closed on the head mean a high, false coupling that can let the trailer drop.

Manual topic: Combination Vehicles - Coupling Inspection · From the Combination Vehicles practice bank (CV-156).

Practice this subject as a full test

More Combination Vehicle Inspection questions

• You see a visible space between the trailer apron (upper coupler plate) and the fifth wheel skid plate after coupling. What does this most likely mean?
• When inspecting the landing gear during a pre-trip inspection of a combination vehicle, what should you check?
• When inspecting the fifth wheel itself, which condition is a defect that must be fixed before driving?
• Why should the fifth wheel skid plate be kept properly greased?
• What should you check about the kingpin during a trailer inspection?