If engine torque is applied to the rear axle to drive a vehicle, what is this axle referred to as?

The term "live axle" refers to an axle that is not only responsible for supporting the vehicle's weight but also plays an active role in driving the wheels. When engine torque is applied to the rear axle, causing it to turn the wheels and propel the vehicle, this axle is termed a live axle. In many vehicles, especially those with rear-wheel drive, the live axle system transmits power from the engine through the driveshaft, enabling the vehicle to move.

This designation is important because it distinguishes the live axle from other types of axles that may serve different functions, such as supporting the vehicle's weight without providing power to the wheels. Understanding the role of the live axle helps technicians and automotive students to grasp the mechanics of vehicle propulsion and design, providing insight into how different axle types operate under load and during driving conditions.