This is a description of CV joints, or constant velocity joints. CV joints are a higher tech and smoother version of the old universal joints that do essentially the same thing. The advent of front wheel drive cars, coupled with the movement toward smoother, more vibration free drive trains, CV joints became necessary. The down side of CV joints is that they require a clean and lubricated environment, and this requires a flexible set of bellows, also called a boot. The boot keeps dirt, water, and other contaminants out of the joint while keeping lubricant in. It also allows the drive shafts to flex with relation to each other. The problem with the boot is that when it fails, it perforates. This allows all the lubricant to leave the joint and allows contaminants in. At best the joint must be dissembled, cleaned and a new boot must be installed. At worst, the contaminants will destroy the joint and the whole assembly will need to be replaced. Some money can be saved by catching the failure during the window that the boot is damaged, but before the joint is. A healthy remanufacturing market has, however, made it economical to repair if the joint is damaged. Either way, a clicking or clunking in the drive train during sharp turns in low speed parking lot maneuvers can be fairly economically repaired. Give us a call, or email.