The outer journals of the shafts are also equipped with splines, threaded into the hubs of the drive wheels and secured in them with large hub nuts.
The inner ends of the drive shafts are equipped with sliding constant velocity joints (CV joints), which provide freedom of both tilting the assemblies at various angles and their longitudinal displacement in a certain range. The main working element of the inner CV joints is a double compensation bearing assembly consisting of ball bearings placed between the inner race and the outer separator. The joints can be disassembled to clean the components and check their condition. In the event of detection of irreparable defects, the failed joint is replaced as an assembly.
The outer ends of the drive shafts are equipped with Rzeppa (pronounced "sheppa") or "Birfield" type CV joints, also consisting of ball bearings placed between the inner race and the outer separator, but the design of these joints, unlike the internal ones, provides only an angular degree of freedom of the components, with a complete lack of longitudinal movement. These joints are not subject to disassembly and must be replaced in the event of malfunction.
The condition of the CV joint protective boots should be checked on a regular basis. If cuts or cracks are detected, the defective boots should be replaced and the joints should be re-packed with fresh grease. Replacement of the boots is carried out after preliminary dismantling of the drive shafts (see section Removal and installation drive shafts).
Note. In car accessory stores you can find CV joint covers of a split design. Such covers can be installed on shafts installed on the car, which is not recommended, since when replacing covers you should always check the internal condition of the joints.
The most typical sign of wear/damage to CV joints, in addition to loss of lubrication, is the appearance of a grinding noise coming from the hub of the front wheels when turning (usually the grinding noise is produced by the inner wheel in terms of the turning radius). It is also possible that such sounds may occur in combination with a sharply increasing vibration during acceleration of the vehicle. To check the condition of the CV joints, grasp the shaft with one hand and the joint housing with the other and, attempting to rotate the components in opposite directions, estimate the amount of play. The presence of any noticeable play indicates wear of the splines or internal components of the bearing assembly. At the same time, inspect the shafts for cracks, deformations and other mechanical damage.