Constant velocity joints, better known as CV joints, are found at the ends of the drive shafts. They are essential to connecting the drive shafts to the transmission and wheels. Because of their function and location, these joints easily wear out over time. They can even break. To ensure that you understand the importance of them, it helps to know a little more about what they do and what happens when something goes wrong with them. There are two types of CV Joints. The Cardinal, which is usually found in heavy trucks and four-wheel drive vehicles and rzeppa CV joints found on most front wheel drive vehicles.