Note: This procedure applies to both front and rear differential gear seals.
1. Loosen the wheel nuts, lift the rear or front with a jack (for rear and front differential respectively) part of the car and install special supports. Block the wheels on the supporting surface to prevent the vehicle from rolling off the supports. Remove the wheels.
2. Disconnect the driveshaft from the differential gear and secure it outside the work area (see subsection 3).
3. Turn the gear several times by hand. Measure the torque required to turn the gear using a torque wrench (see illustration). Record the obtained torque value to use the measurement results during the further procedure.
9.3 Using a torque wrench, measure the torque required to turn the differential gear
4. Mark the initial relative position of the gear flange and shaft (see illustration), then count and record the number of threads visible on the gear shaft.
9.4. Before loosening the nut, mark the initial relative position of the flange and shaft, and also count the number of visible threads
5. Using a special device (available for sale) it is possible to prevent the differential gear flange from turning when the tightening force of the self-locking nut is released. A chain device can also be used to secure the flange (see illustration).
9.5. When loosening the nut, a chain device can be used to secure the flange
6. Unscrew the gear nut.
7. Remove the flange. It may be necessary to use a two-jaw puller that attaches to the flange at the rear to remove it. Do not attempt to remove the flange by prying it or hitting it or the end of the pinion shaft with a hammer.
8. Remove the old seal and discard it (see illustration).
9.8. Using a special puller or a large screwdriver, remove the oil seal located on the differential gear shaft (in this case, the gear should not be allowed to shift)
9. Lubricate the new seal and fill the space between its edges with grease for wheel bearings, then, without allowing it to slant, insert it into the socket using a special mandrel or a large-diameter socket head (see illustration). Make sure that the seal is installed into the housing without tilting and to its full depth.
9.9. To insert a new gear seal into the differential housing, you can use a large-diameter socket head equal to the outer diameter of the seal
10. After aligning the previously applied marks (see item 4), install the gear shaft flange. If necessary, tighten the pinion nut to place the flange in its original location. Do not attempt to drive the flange in with a hammer.
11. Apply RTV sealant to the ends of the spline grooves visible in the center of the flange to create a seal to prevent transmission oil leakage.
12. Install the sealing washer and new pinion nut. Tighten the nut so that the marked number of visible threads remains unchanged (see item 4).
13. Measure the torque required to turn the gear and carefully tighten the nut in small increments (no more than 7 Nm), bring it into line with the value described in point 3. Taking into account the allowance for the new seal to be attracted, tighten the nut so that the torque required to turn the gear slightly exceeds the marked value (no more than 0.5 Nm).
14. Install in reverse order all the elements removed during this procedure. Tighten all fasteners to the required torques.