Adjust preload of tapered roller bearings

AR35.30-B-4302-01XC

Adjust preload of tapered roller bearings

Rear axle

742.824 in model 384.2/3

Rear axle

743.457 in model 384

Modification notes

30.10.2019

Bearing cap the differential assembly housing

BA35.30-B-1010-03H

Rear axle actuation

Number

Designation

Rear axle 742.824

Rear axle 743.453/454/457

BE35.30-B-1001-01F

Backlash between the ring gears

mm

0,20...0,28

0,20...0,28

Rear axle actuation

Number

Designation

Rear axle 742.824

Rear axle 743.453/454/457

BE35.30-B-1002-01F

Satellite box bearings pre-load

Before tightening the rings locks

mm

0,10...0,15

0,10...0,15

After tightening the rings locks

mm

0,075...0,175

-

 Central actuation with differential

Number

Designation

Rear axle 742.82 in vehicle 368.0/1, 384.2/3

Rear axle 743.457 in Vehicle 384.2

BA35.30-B-1010-03H

Bearing cap to differential assembly housing

M16x1,5x110

Nm

250

250

M18X1,5X120

1st stage

Nm

200

-

2nd stage

° angular

90

-

M20x1,5

1st stage

Nm

-

-

2nd stage

° angular

-

-

M22x1,5

1st stage

Nm

-

-

2nd stage

° angular

-

-

1

Install the   spanner wrenches (4, 5) in the bearing threaded rings.

2

Install the   testing device (2) in the differential set housing.

 Check whether the  testing device (2) seats correctly on the surface of the differential set housing, and whether the stops (3) are perfectly supported on the bearing flanks (6).

 The  dial indicator (1) in the  testing device (2) must be supported by the smaller bearing.

 When installing the  testing device (2), there may be an indication of a small preload, as read from the  dial indicator pointer (1). This situation may happen due to deformities to the bearing shoulders and/or the case. Small variations are accepted.

3

Tighten gradually both threaded rings of the tapered roller bearings until preload prescribed in the  dial indicator (1) is reached. 

4

Rotate the gear a few turns to accommodate the tapered roller bearings and return to the starting position. Observe any fall in the preload. If necessary, correct by actuating the threaded rings.

 If the precharge rated value is exceeded, release the threaded rings and repeat the operations from step 3.

5

Validate the clearance between the teeth of the gear and the pinion and, if necessary, correct and repeat the preload adjustment. 

6

Tighten the .  bearing cap screws to lock the threaded rings.

 Check whether the Allen screws are seated in the threaded rings recesses, ensuring that there is no damage to the thread.