What to know about the Axle/CV Shaft Assembly:
Axle shafts are mostly referred to as “CV axles” or “half-shafts.” An axle shaft is a narrow, pole-like part that joins a wheel to the gears in the transmission. Axles are part of the system that allows the wheels to rotate. One end of the axle shaft is linked to the transmission and the other end is linked 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 be stationary.
Axle shafts are comprised of four parts: shaft, CV joints, grease and the boots (grease container). The most common reason for the axle to malfunction is because of the torn boots (grease leaking out). Without the grease, the CV joints will not get lubricated, dirt will go into the joint and the whole axle will eventually wear out.
Facts to Note:
Your car has multiple axle shafts, but in most cases only one will need to be changed.
Even if the CV joints or boots are the only parts of the axle to fail, it is often advice to change the entire axle.
How to Fix:
Confirm the axle shaft needs to be changed.
Take out wheel and change 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.
Common symptoms indicating you may need to change 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.
Importance of this service:
Axle shafts join 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 be stationary.