Red Seal Transport Trailer Technician Practice Exam

What does the term "drive axle" refer to in trailer terminology?

1. The front axle of the trailer

2. The set of wheels that receive engine power

3. The axle used for steering

4. The axle that supports the trailer load

The correct answer is: The set of wheels that receive engine power

The term "drive axle" specifically refers to the set of wheels that receive engine power, allowing them to propel the trailer forward. In transport trailers, the drive axle is critical for determining how power is distributed from the engine to the wheels, enabling the trailer to move efficiently. This axle plays a key role in traction and stability, particularly during various driving conditions. The front axle of the trailer is typically known as the steering axle and is responsible for navigating the trailer. An axle used solely for steering does not receive engine power, so it does not fit the description of a drive axle. Similarly, while the axle that supports the trailer load is important for distributing weight, it does not inherently involve the transfer of power from the engine. Thus, the definition of a drive axle is firmly established by its function in delivering power to the wheels for movement.