How are CV Axle Assemblies diagnosed?
To diagnose a failing CV axle assembly, a technician will remove the wheel and inspect the CV joint boots for wear and cracks. If the boots are damaged, replacement is indicated. If no visible signs of wear appear, it may be necessary for the technician to take the vehicle for a test drive to evaluate the symptoms. Sometimes a damaged CV axle assembly is noticed during other repairs or inspections.

How is the CV Axle Assembly replaced?
To replace a CV axle assembly, a technician will need access to vehicle-specific repair information. The means of connection between the axle and the transmission differs from one model to the next. For instance, some axles feature a hidden snap ring that retains the axle inside the transmission. The technician will lift and support the vehicle and pull the wheel and tire. The axle nut is removed and the lower control arm ball joint is disconnected so that the wheel hub and steering knuckle can be moved out of the way. The outer end of the axle is pushed through the wheel hub to release it from the front suspension and steering. The axle assembly is supported to avoid damage to the oil seal between the transmission and the axle, and the axle is disconnected from the transmission. A new axle assembly is fitted into place, and the front suspension and steering components are reinstalled. Finally, the hardware is torqued to manufacturer's specifications and any lost fluid is replaced. On some vehicles, additional disassembly of suspension parts might be necessary.
RepairPal Recommendations for CV Axle Assembly issues
RepairPal recommends the use of new replacement CV axle shafts. It is increasingly economical to do so, and new axle assemblies are more reliable than rebuilt units. In addition, there is little advantage to replacing the CV joint boots. The cost of repair is nearly as much as the cost of a new axle, and there is no guarantee that permanent damage has not already been done to the joint.