A constant-velocity (CV) joint, located at each end of a drive shaft, transfers power from the transmission to the wheels at a constant speed, regardless of the angle. This component allows the wheels to steer and suspend independently while maintaining a smooth power delivery. Imagine a shaft connecting two gears; if the shaft were straight, power transfer would be smooth. But if the shaft were bent, the gears would rotate unevenly. The CV joint acts as a flexible coupling, allowing the “bent shaft” (the drive axle flexing with suspension movement) to transfer power smoothly.
This constant-velocity capability is crucial for front-wheel-drive, all-wheel-drive, and many rear-wheel-drive vehicles with independent suspension. Prior to widespread CV joint adoption, universal joints served a similar purpose but created vibrations at higher angles and speeds, limiting steering angles and ride smoothness. This innovation enabled greater design flexibility for vehicle suspension and steering systems, contributing significantly to improved handling, comfort, and the prevalence of front-wheel-drive vehicles.