The steering knuckle joint (CV joint) is used to transmit torque from the front axle differential to the steered wheels with the ability to change the angle of rotation of the wheels. There are hinges of equal and unequal angular velocities.
Constant velocity joints include designs such as "Birfield", "Weiss", "Rzeppa" (named after the author's last name). These designs provide uniform torque transmission over the entire range of operating angles. The most widespread, as the most reliable and providing the maximum resource, is the "Birfield" design, which is installed on the entire range of UAZ vehicles to the present.
The hinges of unequal angular velocities include structures based on crosses, as well as the “Willis Fork” with a ball. The main disadvantage of these designs is the uneven transmission of torque (conditionally by shocks) due to the design, progressing with an increase in the angle of rotation, which negatively affects the resource of the node.
For UAZ Patriot, Pickup, Hunter and cargo series vehicles, Birfield CV joints are installed, which differ only in the length of the axle shaft, while the hinge (grenade) is the same for all models, except for the military (gear) bridge, in which the hinge shaft is shortened, and the splines of the axle shaft are of smaller diameter.
The quality of the CV joint depends on the grade of steel, the accuracy of processing the tracks of the hinge balls, the correctness of the heat treatment, the CV joint for UAZ must have high strength and at the same time the core of the half shaft must work in twisting.