When coupling your tractor to a trailer, once the jaws lock onto the kingpin, what should you do next?
- Lift the landing gear and drive off
- Inspect the lights then move out
- Perform a tug test, then visually confirm the coupling is secure ✓
- Rely on a co-driver to inspect the connection
Answer: C. Perform a tug test, then visually confirm the coupling is secure
After the jaws lock onto the kingpin, do a tug test and then get out to check visually that the coupling is secure.
Why this is the answer
The handbook's coupling procedure has you reverse until the fifth wheel engages, then stretch the tractor and trailer in a tug test to confirm the trailer is locked on. It also requires you to leave the cab and look: there should be no gap above the fifth wheel, the release lever should be locked, and the jaws or latch should be closed around the kingpin. Those checks together tell you the coupling is actually secure before you move.
Why the other answers are wrong
- A. Lift the landing gear and drive off — Lifting the landing gear and driving off skips both the tug test and the visual check the coupling procedure requires after the jaws close.
- B. Inspect the lights then move out — Checking lights does not confirm that the fifth-wheel jaws have closed around the kingpin or that there is no gap above the fifth wheel.
- D. Rely on a co-driver to inspect the connection — The handbook has the driver exit the tractor and visually confirm the coupling, so handing that inspection to a co-driver does not meet the check.
Remember it
Stretch it, then inspect it: no gap above the fifth wheel means the jaws have closed.