AUDI A4 1997 B5 / 1.G 01A Transmission Final Drive Gear Set Owner's Manual

39-163

- Press left tapered roller bearing outer race for
differential (housing side) with shim S2 into
housing Page 39
-126, Fig. 2
. To perform the
measurement use shim S2* with thickness of
1.00 mm (one 0.80 mm shim and one 0.20 mm
shim).

Note:
For measurement specification, a shim S2 of 1.0
mm thickness is initially inserted which will be
designated S2* in the following. After determining
the backlash S2* will be replaced by the correct
shim S2.

- Press in right tapered roller bearing outer race
for differential (final drive cover side) without
shims, until stop Fig. 8, Page 39
-130
.

- Insert differential into housing. Ring gear is
positioned on right side (cover side).

- Install final drive cover and tighten bolts to 25
Nm (18 ft lb).

- Install special tools VW521/4 locking sleeve and 521/8 bushing on
housing side into differential housing.
- Turn final drive housing so final drive cover faces upward.
Pa
ge 21 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-164

- Turn differential 5 turns in both directions to
settle tapered roller bearing.

- Place VW385/17 magnetic plate onto
differential.

- Install measuring tools.
A - Dial indicator extension approx. 30 mm long
B - Hex-head bolt M8 x 45
- Place dial indicator extension on center of VW385/17 magnetic plate.
- Set dial indicator (3 mm measuring range) to "0" with 2 mm preload.

Note:
If the measurement has to be repeated, the differential must again be
turned 5 turns in each direction to settle the tapered roller bearing. - Lift up differential without turning; read off play on dial indicator and
note.
Measurement in following example: 0.50 mm
Pa
ge 22 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-165

Formula:
Stotal
=
S2* + measurement + bearing
preload

Example:

Inserted shim(s) S2* 1.00
mm
+ Measured value 0.50
mm
+ Bearing preload (constant) 0.30
mm
= Total shim thickness Stotal for shims
S1 + S2
1.80
mm
Pa
ge 23 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-166

Determining thickness of shim "S1*"

Notes:

The preliminary shim S1* will be replaced with
the final shim S1 after determining the
backlash.
The total shim thickness Stotal remains
unchanged.

Formula:
S1* = Stotal - S2*

Example:


Total shim thickness Stotal for shims
S1 + S2
1.80
mm
- Inserted shim(s) S2* 1.00
mm
= Thickness of shim S1* 0.80
mm

- Determine shim(s) according to table Page 39
-171
.
Pa
ge 24 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-167

Measuring friction torque

Pinion shaft removed
Differential with shims S1* and S2* installed

Friction torque specifications:
Notes: - Install torque gauge, 0-600 Ncm (53 in. lb)-A- onto differential.
- Read value of dial indicator.
New bearings
Used bearings1)
150-300 Ncm (13-27 in. lb) 30-60 Ncm (3-5 in. lb)
1) Must have run at least 50 km (30 miles) Differential tapered roller bearings are low friction bearings. Therefore
the friction torque only has a limited use as a check. Correct
adjustment is only possible by determining the total shim thickness
Stotal. Do not additionally oil new tapered roller bearings for the friction
torque measurement. The bearings have already been treated with a
special oil by the manufacturer. If the final drive gear set (pinion shaft and ring gear) is being re-
adjusted, the adjustment of the pinion shaft should be checked
Page 39
-153
.
Pa
ge 25 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-168

Adjusting backlash
Position of ring gear in final drive housing

Pinion shaft with shim S3 installed
Differential with shims S1* + S2* installed

- Insert differential into final drive housing, install
final drive cover and tighten all bolts to 25 Nm
(18 ft lb).

- Turn differential 5 turns in both directions to
settle tapered roller bearings.

- Assemble measuring equipment.
- Use VW382/10 dial indicator extension (6 mm flat).
- Set VW388 measuring lever to dimension -a-
Dimension -a-: 60 mm.
- Determine play between teeth flanks as follows:
- Turn ring gear until it makes contact with tooth flank (end of backlash
travel).
- Set dial indicator to "0"with 1 mm preload.
Pa
ge 26 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-169

- Turn ring gear back until contact is made
against opposite tooth flank (backlash).

- Read value of dial indicator and note.

-
Turn ring gear 1/2-turn (90 ) each time and
repeat measurements 3 times.
CAUTION!

If the individual measurements differ by more
than 0.06 mm from each other, the installation
of the ring gear or the final drive set itself is
not correct. Check installation, replace final
drive set if necessary.

Determining average backlash

Example:

1st measurement 0.28 mm
+ 2nd measurement 0.30 mm
+ 3rd measurement 0.30 mm
+ 4th measurement 0.28 mm
= Sum of measured values 1.16 mm

Result: the average backlash is 1.16 mm
4 = 0.29 mm
Pa
ge 27 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-170

Determining thickness of shim "S2"

Formula:
S2
=
S2* - backlash + lift

Example:

Inserted shim S2* 1.00 mm
- Average backlash 0.29 mm
+ Lift (constant) 0.15 mm
= Thickness of shim S2 0.86 mm

- Determine shim(s) according to table. Part
numbers parts catalog
The following shims are available for "S2"

Shim thickness (mm)1)
0.15 0.50 1.50
0.20 0.80
0.25 1.00
1) Using the shim tolerance variations it is
possible to find the exact shim thickness required,
insert two shims if necessary.
Pa
ge 28 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

39-171

Determining thickness of shim "S1"

Formula:
-S1-
=
Stotal - S2

Example:

Total shim thickness Stotal for S1 +
S2 1.80
mm
- Thickness of shim S2 0.86
mm
= Thickness of shim S1 0.94
mm

- Determine shim(s) according to table. Part
numbers parts catalog.
The following shims are available for "S1"

Shim thickness (mm)1)
0.15 0.50 0.90
0.20 0.60 1.00
0.30 0.70 1.20
0.40 0.80
1) Using the shim tolerance variations it is
possible to find the exact shim thickness required,
Pa
ge 29 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18

insert two shims if necessary.
Pa
ge 30 of 31 Final drive
gear set, recommended se
quence for ad
justin
g
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM02.39.18