Home › CDL Practice Tests › Combination Vehicles Questions › Question 10
If you find a gap between the apron and the fifth wheel after coupling, what does it most likely mean?
- A.The fifth wheel needs more grease
- B.The trailer was too high and the kingpin locked in a high, unsafe position
- C.The trailer is too light
- D.The landing gear is too low
Correct answer
B. The trailer was too high and the kingpin locked in a high, unsafe position
Why
When the trailer sits too high, the kingpin can ride over the jaws instead of seating in them. That high hook must be corrected by uncoupling, lowering the trailer, and coupling again.
Manual topic: Combination Vehicles - Coupling · From the Combination Vehicles practice bank (CV-010).