Note. After replacing the shafts, bearings, differential or gearbox housing, it is necessary to adjust the preload of the bearings of the input and output shafts and the differential.
Checking and adjusting the preload of the input and output shaft bearings and differential
Note. These operations are performed using a special tool, shown in the figure.
Press the outer races of the primary and secondary shaft bearings together with the adjusting rings, but without adjusting rings, into the sockets of the clutch housing.
Press the differential bearing outer race together with the adjusting ring into the housing of the gearbox housing using a 68 mm mandrel.
Install differential.
Install the following mandrels on the outer races of the bearings:
- mandrel 49 F 401 383 on the outer ring of the bearing of the input shaft of the gearbox type «F»;
- mandrel 49 F 401 382 A on the outer ring of the bearing of the input shaft of the gearbox type «G»;
- mandrel 49 F 401 382 A on the outer ring of the bearing of the secondary shaft of the gearbox type «F»;
- mandrel 49 G 030 382 on the outer ring of the bearing of the output shaft of the gearbox type «G»;
- mandrel 49 F 401 381 on the outer ring of the differential bearing of the gearbox type «F»;
- mandrel 49 G 030 381 on the outer ring of the differential bearing of the gearbox type «G».
Install the input and output shafts together with the gears into the clutch housing at the same time.
Install spacers 49 F 401 384 on the clutch housing at the points shown in the photo.
Install the gearbox housing.
Screw bolts 49 F 401 386 for gearbox type «F» or 49 V 019 021 for gearbox type «G» and tighten them respectively with a torque of 1.8 - 2.0 kgf·m or 3.8-5.3 kgf·m.
Using two levers 49 F 401 385, turn parts A and B of the mandrels so that the gap indicated in the figure is maximum; no other instrument is allowed to be used.
Rotate the mandrels in the opposite direction until the gaps are sampled.
Turn both parts of the mandrels manually in the same direction until they stop.
Make sure the shafts turn freely.
Use a set of feeler gauges to measure the clearance on the input and output shafts by inserting the feeler gauges between the parts of the mandrels, and record its value.
Determine the thickness of the shim to fit under the outer race of the bearing input shaft according to the formula:
S = A - B,
Where:
S is the thickness of the adjusting ring;
A is the size of the gap between the parts of the mandrel;
B is the thickness of the spring washer.
Example. The gap between the parts of the mandrel is 0.94 mm, the thickness of the spring washer is 0.70 mm.
S = 0.94 - 0.70 = 0.24 mm.
Choose an adjusting ring that is closest in thickness to 0.24 mm, i.e. in this case 0.20 mm.
Determine the thickness of the adjusting ring installed under the outer race of the bearing of the output shaft of the gearbox type «F», which should be as close as possible to the gap between the parts of the mandrel.
For example; if the gap between the parts of the mandrel is 0.39 mm, then an adjusting ring with a thickness of 0.40 mm should be used.
Determine the thickness of the adjusting ring installed under the outer race of the bearing of the output shaft of the gearbox type «G», according to the formula S=AB (see above); B in this case is equal to 0.25 mm.
Insert differential bearing preload adjusters 49 FT 01 515 A and 49 180 510 B into the bore of the side gear.
Using a special dynamometer, measure the differential bearing preload, which should be in the range of 0.03-0.75 Nm.
If necessary, use the two levers 49 F 40 385 to turn both parts of the mandrel until the required bearing preload is obtained.
Measure the gap between the parts of the mandrel at several points with a set of feeler gauges.
Choose an adjusting ring whose thickness should be as close as possible to the largest gap between the parts of the mandrel.
Disconnect the gearbox housing from the clutch housing.
Remove primary and secondary shafts and differential.
Press out the outer races of the bearings.
Instead of setting rings, install matched adjusting rings.
Press the outer rings of the bearings into the appropriate seats.