There are two Mazda CV axle shafts on all front-wheel drive vehicles and four on all-wheel drive vehicles from this automaker. This is the drive components that provide the transfer of motion from the transmission to the wheels so the vehicle will be propelled down the road. The CV axle shaft is the drive component that connects the differential to the wheel hub. A boot covers its joints, and is necessary to keep the grease in position around the knuckle of this joint so it can always be lubricated. If the CV boot is not torn or damaged, the lifespan of the CV axle shaft on your Mazda is generally the same as the vehicle as a whole. Symptoms of a failing CV axle shaft include a banging noise when placing the Mazda into drive or when maneuvering around a corner. This noise is generated from the connected U-joints in the knuckle of the shaft that have excessive wear on them and are no longer tightly connected. This is caused by the lack of grease on them when a CV boot is torn and the grease leaks from this area of your vehicle. The leaking of grease will not only cause damage to this drive component but could also get on your brake rotors impairing the vehicle's ability to stop. The replacement of the Mazda CV axle shaft requires the total disassembly of the front wheel assembly including the suspension components. A good mechanic with the proper tools can complete this procedure in an afternoon. If the Mazda owner does not have the proper tools then the replacement of the CV axle shaft should be carried out at a repair shop or the time required to complete this repair job might take more than a day.