There are problems in the car, which cannot be eliminated by your own efforts. So without special devices you can’t adjust the gearbox. But the rear axle gearbox can be adjusted by the car owner himself. Most expensive car to fix also demands it.
If at the speed of over 30 km/h there is some extraneous noise in the gearbox, it is adjusted. The reason for the malfunction is the operation of the car in severe conditions. For adjustment we will need:
a torque wrench;
a torque wrench; adjusting rings;
The operations are to be carried out in the following order:
cleaning with a brush and kerosene the elements of the mechanism;
replacement of worn parts;
If the gear teeth are no longer sharp, they are sharpened, or the part is replaced;
when reassembling the mechanism, install a spacer sleeve, a new flange nut, and a collar;
when reassembling in an old crankcase, calculate the changes in the pinion and adjusting ring;
under the bearings, using fine sandpaper, smooth out the seating areas until they slip easily;
press the outer rings of the bearings into the crankcase, and the inner rings of the rear bearing into the crankcase
mount the flange from the drive pinion and the inner ring of the front bearing with a nut;
put the crankcase in a horizontal plane;
mount the adjustment ring on the shaft, and put the shaft in the crankcase;
mount the spacer sleeve, front bearing inner ring, collar and pinion flange (in that exact order) and secure the nut;
use a thread attached to the flange neck with a dynamometer to determine the torque of the pinion shaft;
the crankcase and bearings are mounted in the differential housing;
the bearing cap is bolted on;
adjust the differential bearing tension and main gear clearance;
the distance between the caps is measured with a caliper and aligned with the standard;
turn the idler pinion for 3 turns, checking the backlash in the pins of all pairs of teeth;
At the end install the locking plates in place.
Rear axle gearbox is adjusted, hum at high speeds will go away.