1999 AUDI A6 check

39-146


Drive pinion and ring gear,
adjusting

Note:

Careful adjustment of the drive pinion and ring
gear is important for the service life and smooth
running of the final drive. For this reason, the
drive pinion and ring gear are matched together
during manufacture, and checked to ensure a
good mesh pattern and quiet running in both
directions of rotation. The position of quietest
running is found by moving the drive pinion in
an axial direction and at the same time lifting
the ring gear out of the zero-play mesh position
by the amount necessary to maintain the
backlash within the specified tolerance.
The object of the adjustment is to reproduce the
setting for quietest possible running, as
obtained on the test machine in production.
The deviation (tolerance) "r," which is related to
the master gauge "Ro" is measured for the final
drive sets supplied as replacement parts and
marked on the outer circumference of the ring
gear. The final drive set (drive pinion and ring
gear) may only be replaced together as a
matched pair.
Observe the general repair instructions for
Pa
ge 1 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19

39-150
Adjustment overview

Note:
If repairs have been carried out on the final drive it is only necessary to adjust the drive pinion or final drive set if components
have been replaced which have a direct effect on the adjustments of the final drive. Refer to the following table to avoid
unnecessary adjustments:

adjustment required:

Part replaced:

Ring gear
"S1"+"S2"
1)

Page 39
-163

Drive pinion
"S3"
1)
via deviation "r"
Page 39-154

Check backlash


Page 39
-169

Final drive housing X X X
Differential housing X X
Tapered roller bearing for drive pinion X X
Tapered roller bearing for differential X X
Final drive set
2)
X X X
Cover for final drive X X
1) Shims; installation position Page 39
-151
.
2) Drive pinion and ring gear; only replace together.
Pa
ge 6 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19

39-156


- Secure retainer 3304 with two M8 x 30 hex bolts.
- Support final drive when tightening nut (e.g. using universal support
V.A.G 1359/2 in conjunction with transmission jack V.A.G 1383 A).
- Fit a new drive pinion nut.
- Tighten drive pinion nut just far enough so that no play can be felt at
drive pinion.
- Gradually increase tightening torque, checking friction torque at regular
intervals, unti specified friction torque is obtained.

The following friction torques should be set: 1) run at least 50 km (30 miles) A - Torque gauge, commercially available, 0-600 Ncm
B - Extension with 32 mm socketNew bearings
Used bearings
1)
200-250 Ncm 30-60 Ncm
Pa
ge 15 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19

39-159

Determining measurement "e"

Note:
Dimension "e" is required to determine thickness of shim "S3."
Determining shim thickness "S3" - Turn mandrel until dial gauge point touches end measuring plate on
drive pinion head, then measure maximum deflection (return point).
Measured value is dimension "e" (in red scale).

Measurement in following example: "e" = 1.60 mm
- After removing universal mandrel, check once again whether dial
gauge reads "0" with 2 mm preload when master gauge VW 385/30 is
in place, otherwise repeat measurement.
Formula:
"S3"
=
"e" - "r"
e
=
Measured value
r
=
Deviation (tolerance): marked on ring gear in 1/100 mm
Pa
ge 18 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19

39-161

- Remove drive pinion and outer race of large
tapered roller bearing and install together with
measured shims "S3" and spacer sleeve from
Page 39
-139
.
Install inner race of small tapered roller bearing
and tighten nut for drive pinion until specified
friction torque is obtained
Fig. 11 , Page 39
-144
.

Note:

Do not additionally oil new tapered roller
bearings for friction torque measurement. The
bearings have already been treated with a
special oil by the manufacturer.
Increase tightening torque slowly and check
friction torque at regular intervals, if the
specified friction torque is exceeded, the spacer
sleeve must be replaced and the adjustment
repeated. A spacer sleeve which has been
compressed too much cannot be reused.

- Set to following friction torques:

New bearings
Used bearings
1)
200-250 Ncm 30-60 Ncm
Pa
ge 20 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19

39-162

Performing check measurement

Checking dimension "r"

- Turn drive pinion at least 5 turns in both
directions.

- Insert universal mandrel and perform check measurement.
If the shims have been correctly selected, the dial gauge should now
show the value of "r" as marked on the ring gear, reading anti-
clockwise in the red scale, within a tolerance of 0.04 mm.

- Peen drive pinion nut with a punch.
Pa
ge 22 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19

39-163

Ring gear, adjusting

(Adjusting differential)
Repairs after which the ring gear has to be
adjusted Page 39
-150
, Adjustment overview

Note:

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 "S
total
."

Do not additionally oil new tapered roller
bearings for friction torque measurement. The
bearings have already been treated with a
special oil by the manufacturer.

Determining total shim thickness "S
total
" for
shims "S1" + "S2"
(Setting preload of tapered roller bearing for
differential)

Drive pinion removed or ring gear dismantled
from differential housing

- Pull out drive flange oil seal with lever.
Pa
ge 23 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19

39-168

Measuring friction torque (check)

Drive pinion removed
Differential fitted with shims "S1*" and "S2*"

Friction torque specifications: 1) run at least 50 km (30 miles)
Note: - Fit torque gauge 0-600 Ncm -A- onto differential.
- Read friction torque.New bearings
Used bearings
1)
150-300 Ncm 30-60 Ncm
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
"S
total
."
Do not additionally oil new tapered roller bearings for friction torque
measurement. The bearings have already been treated with a special
oil by the manufacturer. If the final drive set (drive pinion and ring gear) is being re-adjusted,
the adjustment of the drive pinion should be performed now, and the
Pa
ge 30 of 38 Drive
pinion and rin
g gear, ad
justin
g
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.TM03.39.19