Fig. 6.12. Front wheel drives: a – left front wheel drive; b – right front wheel drive; 1 – external hinges; 2 – front wheel drive shafts; 3 – internal hinges
The front wheel drives consist of outer 1 (Fig. 6.12) and inner 3 constant velocity joints (CV joints) connected by shafts 2. The outer joint allows only angular movements of the connected shafts. The inner joint, in addition to angular movements, also allows axial displacements of the shafts when turning the front wheels and operating the suspension. The left wheel drive shaft is made of a rod, and the right one is made of a pipe. In addition, the drive shafts differ in length: the right one is longer than the left one.
Fig. 6.13. Front wheel drive: 1 – outer hinge housing; 2 – retaining ring; 3 – clip; 4 – ball; 5 – outer clamp; 6 – separator; 7 – thrust ring; 8 – protective cover; 9 – inner clamp; 10 – wheel drive shaft; 11 – inner hinge lock; 12 – inner hinge housing; 13 – inner joint housing retaining ring; A – control size
The outer joint consists of a housing 1 (Fig. 6.13), a separator 6, an inner race 3 and six balls. Grooves for placing the balls are made in the joint housing and in the race. The grooves in the longitudinal plane are made along the radius, which provides an angle of rotation of the outer joint of up to 42°. The splined tip of the joint housing is installed in the hub of the front wheel and is secured to it with a nut.
The sleeve 3 of the hinge is installed on the splines of the shaft 10 between the thrust ring 7 and the retaining ring 2.
The inner hinge differs from the outer one in that the body and cage tracks are straight rather than radial, which allows the hinge parts to move in the longitudinal direction. This is necessary to compensate for the movements caused by vibrations of the front suspension and power unit.
Balls of the same sorting group are installed in the outer and inner hinges; if necessary, all six hinge balls are replaced; the balls must be of the same sorting group. A selective method is used when assembling the inner hinge. Replacing any one part is not allowed - the inner hinge must be replaced as an assembly.
The hinge parts are lubricated with SHRUS-4 grease, which is placed in the hinge housings during assembly. The hinges are sealed with protective covers secured with clamps.
Note. Drive joints are very durable, their estimated service life is almost equal to the service life of the car. However, they are often replaced or repaired during operation. Such work is expensive and labor-intensive. In order to save a lot, regularly check the condition of the protective covers of the joints and replace them immediately at the slightest damage. If water or dust gets into the joint through a damaged cover, it will fail after several hundred kilometers. A sealed joint wears out extremely slowly.