What is the Axle/CV Shaft Assembly about?

Axle shafts are most commonly referred to as “CV axles” or “half-shafts.” An axle shaft is actually a narrow, pole-like part that links a wheel to the gears in the transmission. Axles are components of the system that allow the wheels to rotate. One end of the axle shaft is linked to the transmission and the other end is attached to the wheel. The transmission rotates the axle shafts, which turns the wheels. Without the axles, the tires will not rotate and the vehiicle will not move.

Axle shafts are comprised of four parts: shaft, CV joints, grease and the boots (grease container). The most common cause for the axle failure is because of the torn boots (grease leaking out). Without the grease, the CV joints will not be lubricated, dirt will enter the joint and the whole axle will eventually wear out.

Bear in mind:

  • Your vehicle 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 components of the axle to fail, it is often recommended to change the entire axle.

How it is done:

  • Verify the axle shaft requires replacement.
  • Remove wheel and change faulty axle.
  • Torque all fasteners and wheels to factory specifications.
  • inspect tire pressure.
  • Go on road test.


Each time you get a major service, the mechanic should carry out 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 worn and require replacement.

What common signs to indicate you may need to change the Axle/CV Shaft Assembly?

  • Loud clicking noise in front or rear of the vehicle when making a turn.
  • You may see grease on the inner edges of the tires.
  • Vibration when you drive.

How vital is this service?

Axle shafts connect your transmission to your car wheels. When you step on the gas pedal, the transmission gears turn the axle shafts, which then rotates the wheels. Broken axle shafts will not turn, and there will be no connection between your transmission and your wheels; as a result, your wheels will not move.