Bearing preload is controlled by the torque of the drive gear (other details are not installed). For new bearings, the turning torque should be within 157–197 N.cm, for bearings after a run of 30 km or more - 39.2–59.0 N.cm. In this case, the shank nut is tightened with a torque of 118–255 N·m, periodically checking the rotation of the drive gear. If the specified turning torque has already been reached and the tightening torque of the nut is less than 118 Nm, it is necessary to replace the spacer sleeve with a new one, as the old one is too deformed. Replacing the bushing is also necessary when the turning torque is higher than the permissible (due to carelessness when tightening).
If the main pair or pinion bearings are replaced, the thickness of the shim must be re-selected. It is mounted on the shaft between the drive gear and the inner ring of the large bearing. The ring selection method is described in the section Disassembly of the rear axle gearbox.
The final drive gear is attached to the differential box flange with special bolts without washers. These bolts cannot be replaced by any other. The differential box rotates in two conical bearings. Their preload, as well as the gap between the teeth of the main gear gears, is regulated by nuts wrapped in split bearing beds. The side gears are installed in the cylindrical sockets of the differential box and rest on it through the support washers. These washers are selected in thickness so that the gap between the teeth of the satellites and side gears is within 0–0.1 mm. Satellites are mounted on axles with constant meshing with side gears. Spiral grooves are made on the axis for supplying lubricant to rubbing surfaces.
The axle shaft rests at one end on a single-row ball bearing installed in the seat of the rear axle beam, and at the other (slotted) end enters the semi-axial gear. The inner ring of the bearing is fixed on the axle shaft with a locking ring installed with an interference fit (hot fit). The outer ring of the bearing is fixed by a plate, which, together with the oil deflector and the brake shield, is fastened with four bolts and nuts to the rear axle beam.
1.3 liters of gear oil of quality class GL-5 are poured into the rear axle housing (practically - to the lower edge of the filler hole). The outputs of the semi-axes from the beam are sealed with glands. If the seals are leaking, the oil is drained through the oil deflector to the outside of the brake shield - this way it does not get on the brake pads. The stuffing box, installed in the neck of the reducer, works on the surface of the flange. An oil deflector is installed between the bearing and the flange. Oil leakage from under the self-locking flange nut (The same nut adjusts the bearing preload) indicates a weakening of its tightening. Operating the vehicle with a loose gearbox nut can result in damage to the gearbox.
To equalize the pressure outside and inside the rear axle housing, a breather is located on the rear axle beam above the gearbox. At every maintenance, check that the breather cap is not stuck.