Maintenance
CV joints require a special type of high temperature, high pressure grease. Ordinary chassis grease or multipurpose grease should never be used in a CV joint.
The condition of the grease as well as the amount of grease in the joint will determine how long the joint lasts. One of the purposes of the boot that surrounds the CV joint is to keep dirt and moisture out. The other is to keep the grease in. If a boot is torn, cracked, punctured or comes loose, dirt and water can contaminate the grease in the joint causing accelerated wear which will eventually lead to joint failure. Loss of grease can also occur which will further shorten the life of the joint. So the boots must be in good condition to protect the joint.
Boots often become brittle with age and exposure to heat. Boots can also be damaged by road hazards and the careless use of j-hooks by a tow truck operator. Old boots should never be reused if a CV joint is being replaced. That is why most new CV joints come with a new boot
