CV Boot refers to the rubber, vinyl, or synthetic rubber boots that keep the grease inside the CV joints on the axles of your car. These axles connect the transmission or differential to the wheels. Most 4WD models also have CV joints on their driveshafts that connect the transmission to the rear differential. Some, like Vanagon Syncros, use U joints, or Universal Joints. Let’s just say that when these CV boots break, the CV joints on the axles will eventually get contaminated, or lose their grease, and wear out. A CV Boot is Cheap. A CV Joint is Expensive.
Many shops just replace the entire axle rather than take the CV joints off and inspect and repack them. It is true that the job of axle service is a lesson in geometry, but in most cases, the joints are fine. The tradeoff is the cost of labor versus the cost of a replacement axle. Most replacement axles are of questionable quality compared to the factory originals. Really the decision to repack or place needs to happen differently considering an number of factors. The value and future of the vehicle is perhaps the most important. The quality of the available replacements is another. And the financial needs of the customer are always a consideration.
At Karmakanix, most of the vehicles we work on are worth removing the axles and disassembling the CV joints. Occasionally we find a failed joint. Factory replacements are always the best solution, but not necessarily the cheapest. We repack your CV joints with Amsoil synthetic grease. The red Amsoil grease has proven itself to be better than the original factory grey grease, and far superior to the black grease found in replacement axles. At each service, your technician inspects the CV boots, and the results are in your customer profile. When we tell you that your CV boots are broken, consider that the cost of the repair is far less than the consequences when the CV joints fail. Ask your Service Advisor for good advice.