What is the CV Boot all about?
The engine produces power by burning fuel, but how does that power transfer to the wheels that propel you? The engine is connected to the transmission or transaxle, where the engine’s rotation can be controlled and directed. There are axle shafts that connect the transaxle to the front wheels on vehicles with front wheel propulsion. A driveshaft connects the transmission to a rear differential on some vehicles, which may also use constant velocity axle shafts depending on design. These axle shafts use a universal joint to be able to continuously rotate despite not being in a straight line with the transmission or differential. When the suspension travels up and down, the universal joint allows the axle shaft to ‘flex’ without binding. This constant velocity, or CV joint, is encased in a rubber boot known as a CV boot. The CV boot is filled with grease to lubricate the CV joint and prevent corrosion inside the boot. There are clamps on either side of the boot to prevent axle grease from leaking. If the CV joint develops a crack or one of the clamps breaks or becomes loose, grease will leak out of the CV boot and can allow water to get into the CV joint.
Keep in mind:
- Moisture is the enemy of your constant velocity joints. Any water in your CV boot can cause premature failure.
- The constant velocity boot is rubber and therefore prone to weather cracking.
How it's done:
The CV Boot is verified that it needs to be replaced. The vehicle is raised and supported on jack stands and the wheel is removed.
The defective CV Boot is removed by removing the axle and disassembling it to replace the boot and clean the joint.
The new CV Boot is installed by packing the joint with CV grease, reassembling the axle, and connecting the new boot.
The CV Boot is tested for operation and the axle is reinstalled onto the vehicle. The tire is installed and the vehicle is removed from the jack stands.
The vehicle is road tested to ensure proper operation of the CV Boot and axle.
Have the CV boots inspected for leaks or cracking when your vehicle is being serviced during regular maintenance checks. If a CV boot is cracked or grease is leaking from the boot, have it replaced by one of our expert technicians.
What common symptoms indicate you may need to replace the CV Boot?
- Axle grease leaking on the ground by the wheels or on the wheel rims
- Wheels bind when making turns
- Metallic clinking sound when accelerating or braking
How important is this service?
The CV boot performs a vital role in propelling your vehicle. If the CV boot is cracked, or leaking and water or debris enter the CV joint, it can bind, seize, or break very soon after. Have the CV boot replaced before additional damage occurs. If additional CV joint damage occurs, you may need to replace the whole axle shaft instead of just the boot.