2. Disconnect the cardan shaft from the gearbox and move it to the side.
3. Check the moment of resistance to turning the wheel by turning the gearbox nut with a torque wrench with a scale of several Nm.
4. Mark the position of the nut, pinion gear and flange.
5. Count the number of threads to the nut.
6. Fix the reducer flange and unscrew the pinion nut.
7. Remove the gearbox flange.
8. Pry up and remove the seal.
9. Lubricate the oil seal and groove in the gearbox housing with grease. Carefully, not allowing displacement of the drive gear of the gearbox, press in a new oil seal until it stops.
10. Install the gearbox flange, matching the marks. It is not allowed to install the flange by blows.
11. Carefully cover the joint of the flange and slots with sealant.
12. Put on the washer and tighten the nut by the number of threads counted before disassembly.
13. Measure the torque at which the drive gear begins to turn. This moment is equal to the preload in the pinion bearings and must be correct. If the torque is less than required, then tighten the reducer nut until the desired torque is reached (maybe a little more than normal but not more than 0.5 Nm.).
14. Further assembly is carried out in the reverse order.