If your tractor has a sliding fifth wheel, what must be verified after repositioning it?

• A.That the locking pins are fully engaged on both sides so the fifth wheel cannot slide under load
• B.That the fifth wheel sits as far rearward as possible
• C.That the trailer apron clears the cab by at least a foot at all times
• D.Nothing; the fifth wheel locks itself when you drive off

Why

A sliding fifth wheel that is not pinned can slam forward or backward under braking or acceleration, shifting weight and possibly damaging the landing gear or cab. Both pins fully seated is the check that matters.

Manual topic: Combination Vehicles - Coupling Inspection · From the Combination Vehicles practice bank (CV-166).

Practice this subject as a full test

More Combination Vehicle Inspection questions

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