Although relatively rare, sometimes the axle (or axles) on a vehicle must be replaced or repaired.
What Is an Axle and What Does It Do?
The axle is a load-bearing component of the rolling chassis that allows the wheels to turn while keeping them connected to the vehicle. Drive axles are those through which engine power is sent in order to turn the wheels. On most vehicles, the axles are straight shafts of metal with gear teeth on one or both ends, depending on whether the axle is a drive or not.
Axles maintain the position of the wheels while allowing them to turn and are the primary component that keeps the wheels in alignment and turning. They are simple, strong components with no moving parts other than themselves turning.
What Can Go Wrong With An Axle?
In the unusual case of an axle requiring replacement, it's usually due to an accident which has bent the axle or compromised its strength (as in the case of fire or an accidental welding slip). Axles are literally just long metal rods, so for them to become damaged is unusual outside of serious accidents.
In the case of drive axles, however, a common problem is the breaking or bending of the axle's teeth, causing it to no longer properly grip the wheel hub, CV or differential. In this case, it is usually because contaminants have entered the gearing and caused friction and wear.
What Does It Take to Replace an Axle?
Most competent DIY mechanics can replace an axle in a couple of hours, depending on the vehicle. Drive axles require more time and know-how, but most of the work is actually getting to and the axle itself, not removing or replacing it.
If the axle has been combined with the transmission to create a transaxle, the job becomes much more complex and may require specialized tools or training.