1. Lubricate a pair of teeth on the final drive crown gear with ink.
2. Rotate the drive gear back and forth while restraining the driven gear with a special holder (601 589 01 40 00).
3. Compare the resulting tooth contact patches with the map below.
Normal engagement (the result can be considered satisfactory when the contact spots do not go beyond the edges of the working surfaces of the teeth)
Displacement of contact spots to the bases of the teeth, - the value of the base landing size of the drive gear is insufficient (make the appropriate adjustment and repeat the check, after checking the engagement play - see Section Removal and installation of assemblies of cross-axle differentials with driven gears of main gears)
Displacement of contact spots to the tops of the teeth, - the value of the base landing size of the drive gear is excessive (make the appropriate adjustments and repeat the check, after checking the engagement play - see Section Removal and installation of assemblies of cross-axle differentials with driven gears of main gears)
Displacement of contact spots to the heels of the teeth, - excessive backlash of gear engagement (make the appropriate adjustment - see Section Removal and installation of assemblies of cross-axle differentials with driven gears of main gears, - and check again)
Offset of contact spots to the toes of the teeth, - insufficient amount of backlash of the gear engagement (make the appropriate adjustment - see Section Removal and installation of assemblies of cross-axle differentials with driven gears of main gears, - and check again)