A broken axle refers to an axle that is bent, cracked or otherwise unable to function properly. In cars, axles are responsible for turning the wheels in response to the movement of the steering wheel. There are two kinds of axles: a drive axle and a dead axle.
The drive axle has two ends with CV joints, which are also known as constant velocity joints. These joints are covered by a rubber boot and connect to the driveshaft and wheels. When the steering wheel of a car is turned, the motion is transferred from the driveshaft to the axle and CV joints, which causes the wheels to turn. When this type of axle is broken or damaged, the wheels of a car are very difficult to turn. Additionally, a damaged or broken axle may cause the CV joints to weaken. This problem usually causes a clicking sound when the wheels are turned.
On the other hand, dead axles are not connected to the engine and are mainly designed to bear the weight of the vehicle. Heavier vehicles often have multiple dead axles to support the vehicle. One difference between the dead axle and the drive axle is the wheels connected to the dead axle can only be turned when the engine is running. The wheels connected to the drive axle can move when the engine is off.
An axle does not typically wear out over time and does not need to be replaced at specific intervals. Axles are only damaged when a car is in an accident or a vehicle drives over a large bump at high speeds.