Adjust gear backlash at differential assembly

AR35.30-B-0475XD

Adjust gear backlash at differential assembly

25.08.2016

Rear axle

748.590/594 in model 934.2, 958.4

1

Differential set case

2

Taper roller bearing

3

Bearing cover

4

Threaded ring

5

Bolt

6

Sprocket

7

Dial gauge

8

Gauge holder

9

Threaded ring

4

Threaded ring

10

Bolt

11

Safety lock



Measure

 Danger !

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 gage support (8) with the dial indicator (7) on the flat surface of the differential set case (1)

 The dial gauge (7) must be in the vertical position with its tip supported on the flank of a ring gear tooth (6) with a pre-load of approx. 2mm.

 Dial gage

*001589532100

 Dial indicator holder

*363589022100

2

Turn the differential set various turns, and carry out the measurement of the clearance between the teeth of the ring gear (6) and the pinion, at least at three different points, 120° far from each other

 Determine the lowest play point between the measured points.

Ring gear teeth clearance

*BE35.30-B-1001-01K

3

Block the pinion at the lowest clearance point between the teeth in the differential set and adjust the clearance moving axially the differential set through the threaded rings (4, 9) until obtaining the lowest prescribed clearance


When adjusting the differential set teeth flank clearance, try to obtain a clearance as close as possible to the lowest prescribed clearance.
This is due to the fact that after the adjustment of the tapered roller bearings pre-load regulation, the clearance between the ring gear teeth (6) tends to increase.

 Claw wrench

*055589160700

 Claw wrench

*055589150700

4

Tighten the bearing cap screws (5) up to the prescribed torque (1st step)

 Differential mounting bearing cap

*BA35.30-B-1004-03L

5

Determine the differential set mounting measure

AR35.30-B-0475-01XD

6

Adjusting the pre-load of tapered roller bearings

AR35.30-B-4302-01XD

7

Tighten bearing cap bolts (5) up to the specified tightening torque (2nd step)

 If not already fitted.

 Differential mounting bearing cap

*BA35.30-B-1004-03L

8

Install the lock plate (11), and tighten threaded rings (4, 9) bolt (10)

 Safety lock bolt to bearing cap

*BA35.30-B-1003-03L



Check

9

Turn the differential set some times and check again the clearance between the ring gear (6) teeth flanks and the pinion

 If the nominal value has not been reached, repeat the operations from the step 3 on.

Rear axle actuation

Number

Designation

Rear axle 748.590/594 in model 934.2, 958.4

BE35.30-B-1001-01K

Ring gear teeth clearance

mm

0,25...0,33

 Central actuation with differential

Number

Designation

Rear axle 748.590/594

BA35.30-B-1003-03L

Safety lock bolt to bearing cap

M8

Nm

25

 Central actuation with differential

Number

Designation

Rear axle 748.590/594

BA35.30-B-1004-03L

Differential mounting bearing cap

M22x1.5

1st stage

Nm

200

2nd stage

° angular

90