Red Seal Truck and Transport Mechanic Practice Exam

What is the recommended torque specification for wheel nuts on heavy-duty trucks?

1. Typically between 250 to 350 ft-lbs, depending on the vehicle and wheel type

2. Typically between 450 to 600 ft-lbs, depending on the vehicle and wheel type

3. Typically between 300 to 400 ft-lbs, depending on the vehicle and wheel type

4. Typically between 150 to 200 ft-lbs, depending on the vehicle and wheel type

The correct answer is: Typically between 450 to 600 ft-lbs, depending on the vehicle and wheel type

The recommended torque specification for wheel nuts on heavy-duty trucks typically falls between 450 to 600 ft-lbs, depending on the specific vehicle and wheel type. This range is important because heavy-duty trucks experience significant weight and stress during operation, necessitating a higher torque to secure the wheels properly. Adequate torque ensures that the wheel nuts are tightened sufficiently to withstand the dynamic loads while the vehicle is in motion. Using the appropriate torque not only helps prevent wheel separation but also minimizes the risk of wheel nut loosening over time due to vibrations. It's essential to consult the manufacturer's specifications for the specific truck model, as different vehicles can have different requirements based on their design and weight distribution. In contrast, lower torque values may not provide the necessary grip, leading to potential safety hazards, including wheel detachment. This is why other specifications that suggest lower torque ranges do not meet the robust needs of heavy-duty applications.