CDL Combination Vehicles TestCoupling and UncouplingEasy
During the coupling process, if the trailer's nose is too high relative to the fifth wheel, what is the most appropriate corrective action?
- ABack the tractor up further and try to force the connection.
- BLower the trailer's landing gear to reduce its height.
- CAdjust the fifth wheel height on the tractor.
- DRaise the trailer's landing gear to increase its height.
Show answer & explanationAnswer & explanation
Correct answer: B. Lower the trailer's landing gear to reduce its height.
If the trailer's nose is too high, it means the trailer is sitting too tall for the fifth wheel to properly engage the kingpin. The correct action is to lower the trailer's landing gear to bring the trailer's nose down to the correct height.
Why the other options are wrong
- A. Forcing the connection can damage the fifth wheel, kingpin, or frame.
- C. Adjusting fifth wheel height is a more complex procedure and usually not the first or easiest solution for a temporary height mismatch.
- D. Raising the landing gear would make the trailer even higher, exacerbating the problem.
Trailer Height Adjustment
The process of using the trailer's landing gear to set its height appropriately for coupling or uncoupling.
- Crucial for proper kingpin alignment.
- Prevents damage during coupling.
- Adjusted via landing gear crank.
Memory trick: Too high, go low. Too low, go high.