A front axle boot, also known as a constant velocity (CV) boot, is a rubber cover that goes over the drive axle or CV joint on a car. The boot protects the joint and keeps grease used to lubricate the joint where it belongs, near the friction points.
The front axle boot is fitted to the diameter of the drive axle so that it covers the moving parts of the axle. The boot prevents debris from getting near the drive axle and keeps grease packed near the axle's moving parts.
There are two types of front axle boots. The first is an OEM, custom-fit boot. This requires partial disassembly of the front axle shaft to install. The second type is split down the middle so it may slide over the front axle shaft without requiring disassembly. After installing this type of boot, it is permanently attached with glue or small nuts and bolts.
The front axle boot may be seen while turning your wheels all the way left or right. It is a flexible rubber boot just on the inside of each front wheel.
The front axle boot prolongs the life of a drive axle. Without its protection, the axle would run without lubrication and the vehicle would be inoperable.
Have your mechanic inspect the front axle boot at each oil change. If you do your own service, check the boot regularly. Catching a torn boot and leaking grease can keep you from needing more expensive repairs at a later time.
