Adjust gear backlash at differential assembly

AR35.30-B-0475SP

Adjust gear backlash at differential assembly

02.01.2020

Rear axle

772.117 in model 979.272/277

with code A59 (Rear axle Meritor MS 06.11x3)

with code A74 (Meritor rear axle self-locking differential)

Modification notes

19.12.2019

Clearance between ring gear/pinion

BE35.31-B-1001-03SP

1

Gauge holder

2

Dial gauge

3

Sprocket

4

Adjustment ring



Measure

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

1

Place the dial gauge holder (1) with the dial gauge (2) on the flat surface of the ring gear housing (3)

 The dial gauge (3) should be upright with the contact point rested on the flank of one tooth of the ring gear (3) with a preload of approximately 2 mm.

 Dial gage

*001589532100

 Dial indicator holder

*363589022100

2

Measure the ring gear (3) and pinion backlash

 For measuring the backlash, move the ring gear (3) alternately forwards and back.

 Perform the measurement at four points displaced 90° from each other, on the ring gear rotation direction.

 When measuring it, determine the point with the smaller backlash.

.Clearance between ring gear/pinion

*BE35.31-B-1001-03SP

3

Block the pinion on the point with the smaller backlash and displace the differential case in axial direction by turning the adjustment threaded rings (4) with a proper wrench

 Displace the differential case until getting a backlash 0.05 mm above the maximum specified tolerance.

.Clearance between ring gear/pinion

*BE35.31-B-1001-03SP

 Claw wrench

*055589140700

4

Loosen the threaded rings (4) to relieve the load on the bearings, next prop them again

 Pull gently the threaded rings to not carry load on the bearings.

5

Adjusting the preload of tapered roller bearings

.

AR35.30-B-4302-01SP

.Satellite box bearings pre-load

*BE35.30-B-1001-01SP

6

Lock the adjustment threaded rings (4) with the securing bolts

 .Fastening bolt of the adjustment ring

*BA35.31-B-1002-02SP



Check

7

Spin the ring gear (3) a few times and check again the ring gear and pinion backlash

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

.Clearance between ring gear/pinion

*BE35.31-B-1001-03SP

8

Check the contact marks between the ring gear (3) and the drive pinion

.

AR35.30-B-0475-02SP

Rear axle actuation

Number

Designation

Rear axle 772.117 in Vehicle 979.272/277

BE35.30-B-1001-01SP

Satellite box bearings pre-load

mm

0.200

Differential ring ear and pinion check values

Number

Designation

Rear axle 772.117 in Vehicles 979.272/277

BE35.31-B-1001-03SP

Clearance between ring gear/pinion

Values for new set

mm

0,13...0,25

Values for used set

mm

0,20...0,46

 Differential box

Number

Designation

Rear axle 772.117 in Vehicles 979.272/277

BA35.31-B-1002-02SP

Fastening bolt of the adjustment ring

M16x2.0

Nm

310