CDL Combination Vehicles TestCoupling and UncouplingHard
After successfully coupling a tractor and trailer, a driver should ensure there is sufficient clearance between the tractor's rear frame and the trailer's landing gear. What is the minimum recommended clearance?
- AAt least 6 inches.
- BAt least 8 inches.
- CAt least 4 inches.
- DAt least 2 inches.
Show answer & explanationAnswer & explanation
Correct answer: C. At least 4 inches.
A minimum of 4 inches of clearance is recommended between the tractor's rear frame and the trailer's landing gear. This prevents damage during turns or when traveling over uneven terrain.
Why the other options are wrong
- A. While more is better, 6 inches is not the minimum standard.
- B. 8 inches is excellent but not the required minimum.
- D. 2 inches is generally considered insufficient and risky.
Landing Gear Clearance
The minimum vertical space required between the top of the tractor's rear frame and the bottom of the trailer's landing gear when coupled, typically 4 inches.
- Prevents collision during turns.
- Essential for uneven terrain.
- Checked after coupling.
Memory trick: Four inches or more, for safety's score.