Adjust preload of tapered roller bearings

AR35.30-B-4302-01XB

Adjust preload of tapered roller bearings

Rear axle

742.825 in model 368.0/1, 384.2/3

Rear axle

746.881/882 in model 368.0/1

Rear axle

746.984/999 in model 384.0

Rear axle

746.987/988/996/998 in model 958

Modification notes

30.10.2019

Safety locking bolt to the bearing cover

BA35.30-B-1009-03H

30.10.2019

Bearing cap the differential assembly housing

BA35.30-B-1010-03H

Rear axle actuation

Number

Designation

Rear axle 746.270/271/881/882/984/987/988/996/998/999

Rear axle 742.825

BE35.30-B-1001-01A

Differential ring gear teethplay

mm

0,20 ... 0,28

0,20 ... 0,28

Rear axle actuation

Number

Designation

Rear axle 746.270/271/881/882/984/987/988/996/998/999

Rear axle 742.825

BE35.30-B-1002-01A

Satellite box bearings pre-load

New taper roller bearings

mm

0,025 ... 0,100

0,025 ... 0,100

Used taper roller bearings

mm

-

-

 Central actuation with differential

Number

Designation

Rear axle 746.881/882/888 in type 368.0/1

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

BA35.30-B-1009-03H

Safety locking bolt to the bearing cover

Nm

25

-

 Central actuation with differential

Number

Designation

Rear axle 746.984/987/988/996/998/999 in vehicle 384.0, 985.0/1

BA35.30-B-1009-03H

Safety locking bolt to the bearing cover

Nm

25

 Central actuation with differential

Number

Designation

Rear axle 746.881/882/888 in type 368.0/1

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

BA35.30-B-1010-03H

Bearing cap to differential assembly housing

M16x1,5x110

Nm

-

250

M18X1,5X120

1st stage

Nm

200

200

2nd stage

° angular

90

90

M20x1,5

1st stage

Nm

-

-

2nd stage

° angular

-

-

M22x1,5

1st stage

Nm

-

-

2nd stage

° angular

-

-

 Central actuation with differential

Number

Designation

Rear axle 746.984/987/988/996/998/999 in vehicle 384.0, 985.0/1

BA35.30-B-1010-03H

Bearing cap to differential assembly housing

M16x1,5x110

Nm

-

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  adjusting device (2) on the bearing flanks of the differential assembly housing (3).

 The  dial gauges (1) on the  adjusting device (2) must be previously set to zero by using the  indicated jig.

 Observe the correct seating  of the adjusting device (2) on the flange of the differential assembly housing (3) by means of the pins (4). When installing the  adjusting device (2) there should be no pre-load on the tapered roller bearings.

 Before adjusting the pre-load of the tapered roller bearings, it is necessary to perform the pre-tightening (1st stage) of the bearing cap screws (5) and a pre-adjustment of the backlash between teeth of the ring gear and pinion.

2

Gradually tighten the threaded ring (6) with the  quadrangular mandrel (7) up to get a pre-load (A) on the  dial gauges (1)
. 

 Keep the lowest indicated value for preload (A), so that after final screw (5) torque (2nd step) the nominal value is not exceeded.

3

Turn the ring gear a few times to accommodate the bearings and return to starting position, note if there was a preload falling. If necessary, correct it using the threaded ring (6).

4

Tighten the bearing cap screws (5) using prescribed torque (2nd step). . 

5

Check again the pre-load.

 The amount found out must fall within the indicated nominal value. If the nominal value is exceeded, loose the threaded ring (6) and repeat instructions from the step 2.

6

Remove the  adjusting device (2) and check the backlash of teeth between the ring gear and pinion is according to the specified value
. 

 If the nominal value has not been reached repeat the instructions from the step 2.

7

Install safety locks of the threaded rings.
. 