differential AUDI A4 1998 B5 / 1.G 01W Transmission Pinion Shaft Ring Gear Adjustment Workshop Manual

39-33
List of adjustments

Note:
If repairs have been carried out on the transmission, it is only necessary to adjust the pinion shaft, ring gear or gear set if
components have been replaced that directly influence the final drive adjustment. To avoid unnecessary adjustments, refer to
the following table:

Component to be adjusted:

Component replaced:

Ring gear
"S1"+ "S2" 1)

Page 39
-52

Pinion shaft
"S3"+ "S4" 1)
via deviation "r"
Page 39
-35

Pinion shaft
"S4" 1)

Page 39
-49

Backlash measurement

Page Page 39
-58

Transmission housing 3) X X X
Transmission cover X
Differential housing X X
Tapered roller bearing for pinion shaft X X
Tapered roller bearing for differential X X
Gear set 2)
X X X
Cover for final drive X X 1) Adjustment shims: installation position Page 39
-32
.
2) Replace pinion shaft and ring gear together as a set only.
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39-34

Sequence for adjusting gear set


If pinion shaft and gear ring have to be adjusted, the following sequence
is recommended for maximum efficiency:
Note:
Overview of components and shims Page 39
-32
. 1.) Determine total shim thickness Stotal for S1 + S2 (adjusting preload
for tapered roller bearing for differential) Page 39
-53
.
2.) Determine total shim thickness Stotal for S3 + S4 (adjusting preload
for tapered roller bearing for pinion shaft) Page 39
-37
.
3.) Distribute total shim thickness Stotal for S3 + S4 so that the
dimension between the center of the gear ring and the face of the
pinion shaft equals dimension "R" which was determined during
production Page 39
-45
.
4.) Distribute total shim thickness Stotal S1 + S2, so that the specified
backlash between ring gear and pinion shaft is maintained Page
39
-61
.
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39-37

Determining total shim thickness Stotal for
shims S3 + S4

- Adjust preload of tapered roller bearing for
pinion shaft.

Differential removed

- Pressing on double tapered roller bearing inner
race Page 35
-21
.

Note:
The illustration shows the pinion shaft without gears. - Secure lower tapered roller bearing (arrow).

Pressure plates with a thickness of 14.8 mm or 15.3 mm can be installed. - Install tapered roller bearing outer race for pinion shaft without shims
into transmission housing Fig. 3, Page 35
-30
.
- Install rubber washer (item 40 , Page Page 35
-28
) and pressure
plate (item - 39 -, Page Page 35
-28
) into transmission cover.
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39-44


Note:
Make sure gauge contact surface is precisely installed and free of oil. - Place end gauge on face of pinion shaft.

Note:
For transmissions with drive flange without polygon bearing ( Page 00
-
3 ) use VW385/2 centering disc instead of VW385/3 centering disc
opposite dial indicator. - Remove master gauge and install measuring mandrel into transmission
housing.
Dial indicator extension -A- = 6.5 mm long must be installed VW385/3 centering disc faces cover for final drive
- Install differential cover and tighten 4 bolts to 22 Nm (16 ft lb).
- Using adjustable ring, pull 2nd VW385/3 centering disc out as far as
possible, so mandrel can only just be turned by hand.
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39-52

Ring gear, adjusting


Adjusting differential
For a list of the repairs which will require the ring
gear to be adjusted Page 39
-33
, List of
adjustments

Special tools and equipment

VW382/10 dial indicator extension
VW385/17 magnetic plate
VW387 dial gauge holder
VW388 measuring lever
VW402 thrust plate
VW408A punch
VW472/1 pressure piece
VW521 adjustment tool
3177 clamp
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39-53

Determining total shim thickness Stotal for
shims S1 + S2
(Adjust preload of tapered roller bearing for
differential)

Pinion shaft removed

Note:
If only the differential tapered roller bearings are
to be replaced, remove ring gear from differential
housing. The pinion shaft does not have to be
removed.

- Remove seals and outer races from both
tapered roller bearings for differential.

- Remove shims Page 39
-15
.

Note:
A shim S2 with a thickness of 1.20 mm is installed for initial measurement.
It is referred to in the following text as S2*. After determining backlash, S2*
is replaced with the appropriate shim S2. - Drive in tapered roller bearing outer race together with shim S2 into
transmission housing Fig. 3, Page 39
-23
. Use shim "S2*" with
1.20 mm thickness for measurement purposes (2 shims with 0.60 mm).
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39-54


- Press in tapered roller bearing outer race into differential cover without
shim S1 Fig. 9
, Page 39
-26
.
- Install differential into transmission housing without Vehicle Speed
Sensor (VSS) -G22- gear drive. Ring gear is located on left side in front
of final drive cover.
- Install cover for differential and tighten four bolts to 25 Nm (18 ft lb).
- Position transmission so that cover for differential faces upward.
- Turn differential 5 rotations in each direction to seat tapered roller
bearing.

Note:
Tip of dial indicator must be positioned on the center of the differential. - Assemble measuring equipment, use 30 mm dial indicator extension.
- Set dial indicator (3 mm measuring range) -A- to 0 with 2mm preload.
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39-55

- Lift differential without turning it, read play on
dial indicator and note.
Dimension in the following example: 0.62 mm

Notes:

To lift differential, secure VW521/4 locking sleeve and VW521/8
bushing (for transmissions without polygon bearing) or VW521/12 (for
transmissions with polygon bearing) to right side of differential
(housing side). If measurement has to be repeated, turn differential again 5 rotations
in both directions to seat tapered roller bearing.
Formula:
"Stotal"
=
"S2*" + measured value + bearing preload
Example:

Installed shim "S2*" 1.20 mm
+ Dimension 0.62 mm
+ Bearing preload (constant) 0.30 mm
=
Total shim thickness "Stotal" for "S1 + S2"
2.12 mm
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39-57

Measuring friction torque (check
measurement)

Notes:

Tapered roller bearings for differential are low-
friction. Measurement of friction torque only has
a limited use as a check. Correct adjustment is
only possible by determining the total shim
thickness "Stotal."
Do not lubricate new tapered roller bearings for
measuring friction torque. The bearings have
already been treated by a special oil by the
manufacturer.
Pinion shaft removed

Friction torque specified values:
Note: - Install torque gauge 0-600 Ncm -A- on differential.
- Read friction torque.New bearings
Used bearings
200 - 350 Ncm 30 - 60 Ncm
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39-58

Measuring backlash
(Position of ring gear in transmission housing)

Pinion shaft with shims "S3*" and "S4*"
installed

- Install differential.

- Turn differential 5 rotations in each direction to
seat tapered roller bearing.

- Secure VW387 dial gauge holder on housing.
- Install VW521/4 locking sleeve and VW521/8 bushing (for
transmissions without polygon bearing) or VW521/12 (for transmissions
with polygon bearings).
- Install dial indicator with VW382/10 extension pin, 6 mm.
- Set VW388 measuring lever to dimension "a:"Dimension "a"
Ring gear diameter
67 mm 170 mm
72 mm 180 mm
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