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What is the trailer apron (upper coupler plate)?
- A.The flat steel plate on the underside front of the trailer that slides onto the fifth wheel and carries the kingpin
- B.A cloth cover for the trailer front
- C.Part of the tractor mud flap
- D.The plate that covers the spare tire
Correct answer
A. The flat steel plate on the underside front of the trailer that slides onto the fifth wheel and carries the kingpin
Why
The apron is the trailer's half of the fifth wheel interface and carries much of the trailer's front weight. It must be flat, undamaged, and properly seated on the fifth wheel plate.
Manual topic: Combination Vehicles - Coupling Equipment · From the Combination Vehicles practice bank (CV-113).