What is the Axle/CV Shaft Assembly all about?
Axle shafts are commonly referred to as “CV axles” or “half-shafts.” An axle shaft is a narrow, pole-like part that connects a wheel to the gears in the transmission. Axles are part of the system that enables the wheels to rotate. One end of the axle shaft is connected to the transmission and the other end is connected to the wheel. The transmission rotates the axle shafts, which rotates the wheels. Without the axles, the tires will not rotate and the car will not move.
Axle shafts are comprised of four components: shaft, CV joints, grease and the boots (grease container). The most common reason for the axle to fail is because of the torn boots (grease leaking out). Without the grease, the CV joints will not get lubricated, dirt will enter the joint and the whole axle will eventually wear out.
Keep in mind:
- Your car has multiple axle shafts, but in most cases only one will need to be replaced.
- Even if the CV joints or boots are the only parts of the axle to fail, it is often recommended to replace the entire axle.
How it's done:
- Verify the axle shaft needs to be replaced.
- Remove wheel and replace faulty axle.
- Torque all fasteners and wheels to factory specifications.
- Check tire pressure.
- Perform road test.
Every time you get a major service, the mechanic should perform a basic safety inspection that includes a visual inspection of the axles and boots. If there is grease found around the tires, it is likely that CV boots are leaking. Also, if you hear a loud clicking noise when you make a turn, it can mean that the axles are bad and need replacement.
What common symptoms indicate you may need to replace the Axle/CV Shaft Assembly?
- Loud clicking noise in front or rear of the car when making a turn.
- You may notice grease on the inner edges of the tires.
- Vibration when driving.
How important is this service?
Axle shafts connect your transmission to your wheels. When you step on the gas pedal, the transmission gears turn the axle shafts, which then turn the wheels. Broken axle shafts will not rotate, and there will be no connection between your transmission and your wheels; as a result, your wheels will not move.