CDL Vehicle Combination Practice Test

What can cause damage to the landing gear during coupling?

1. High speeds while coupling

2. Backing under the trailer at an angle

3. Excessive weight on the landing gear

4. Poor visibility during the process

The correct answer is: Backing under the trailer at an angle

Backing under the trailer at an angle can indeed lead to damage to the landing gear during the coupling process. When a driver approaches a trailer at an angle, the alignment between the tractor's fifth wheel and the trailer's kingpin can be compromised. This misalignment can cause undue stress or strain on the landing gear, which is designed to support the trailer when it is not connected to a towing vehicle. If the landing gear is under uneven pressure or is forced to twist as the tractor moves into position, it can bend or break, leading to mechanical failure. In contrast, high speeds while coupling, excessive weight on the landing gear, and poor visibility can contribute to safety issues or operational difficulties, but they do not directly result in damage to the landing gear in the same manner that improper alignment does. Proper technique involves ensuring the vehicle is positioned correctly with respect to the trailer to prevent such damage.