A half shaft, also called an axle, transmits power from the transmission to propel the vehicle's wheels. Each half shaft has two constant-velocity (CV) joints, which are packed with grease and encapsulated by a rubber cover known as a CV boot.
To replace a worn CV joint, the wheel is removed and the suspension is disassembled to the point where the half shaft can be withdrawn from the transmission and suspension. The half shaft is cleaned and disassembled, and a new CV joint is fitted. Then the half shaft is reassembled and installed in the vehicle, and the suspension is reassembled.