AUDI A4 1999 B5 / 1.G 01A Transmission Final Drive Ring Gear Pinion Shaft Workshop Manual

39-34


Front final drive ring gear and
pinion shaft, adjusting

Notes:

Careful adjustment of the pinion shaft and ring
gear is essential for the service life and smooth
running of the final drive. For this reason, the
pinion shaft and ring gear are matched together
during manufacturing, 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 pinion shaft 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 objective of the adjustment is to reproduce
the setting for quietest possible running, as
obtained on the test machine during production.
The deviation, or tolerance "r", which is based
on 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 (pinion shaft and
ring gear) must only be replaced together as a
matched pair.
Observe the general repair instructions for
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tapered roller bearings and shims.
The friction torque measurement only serves to
give a final check of the adjustment.
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39-35


Adjustment and marking of final drive gear
sets

1 -
Identification "0937" signifies an Oerlikon
gear set with a ratio of 37:9
2 -
Pairing number (312) of final drive gear
set
3 -
Deviation (tolerance) "r" is based on the
test machine master gauge used during
production. The deviation "r" is always
given in 1/100 mm. Example: 25 signifies r
= 0.25 mm
Ro - Length of test machine master gauge
used
Ro - For 170 mm (6.69 in.) diameter ring
gear = 54.95 mm (2.16 in.)
R - Actual dimension between ring gear
axis and face of pinion shaft in position
of quietest running for this gear set.
Vo - Hypoid offset
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39-36


Installation position of shims

Note:
List of adjustments when replacing individual
components of transmission Page 39
-37
.
S1 - Shim for ring gear in differential cover
S2 - Shim for ring gear in transmission
housing
S3 - Shim for pinion shaft in transmission
housing
S4 - Shim for pinion shaft in transmission
cover
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39-37
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 final drive set if
components have been replaced that have a direct effect on the adjustment of the final drive. Refer to the following table to
avoid unnecessary adjustments:
Component to be adjusted:



Component to be adjusted: Ring gear
(S1 + S2)1)


Page 39
-
57

Pinion shaft
(S3 + S4)1)
via deviation
"r"

Page 39
-39


Pinion shaft
(Shim S4)1)


Page 39
-
54

Backlash
measurement


Page 39
-63

Transmission housing3) X X X
Transmission cover X
Differential housing X X
Double tapered roller bearing for pinion shaft and
hollow shaft X X
Tapered roller bearing for differential X X
Final drive set2)
X X X
Differential cover X X
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1) Shims, installation position Page 39
-36
.
2) Pinion shaft and ring gear, only replace together. 3) If the transmission housing is replaced, the input shaft must also be adjusted input shaft, adjusting, Page 35
-17
.
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39-38

Final drive gear set, recommended
sequence for re-adjusting


If the pinion shaft and ring gear have to be readjusted, the following
sequence is recommended for maximum efficiency:
Note:
Overview of components and shims Page 39
-36
. 1.) Determine total shim thickness Stotal for S1 + S2 (adjusting preload
for tapered roller bearings for differential) Page 39
-58
.
2.) Determine total shim thickness Stotal for S3 + S4 (preload for
tapered roller bearings for pinion shaft) Page 39
-41
.
3.) Distribute total shim thickness Stotal for S3 + S4 so that the
dimension from center of ring gear to face of pinion shaft is the
same as dimension "r" which was determined during production
Page 39
-49
.
4.) Distribute total shim thickness Stotal for S1 + S2 so that the
specified backlash between ring gear and pinion shaft is maintained
Page 39
-65
.
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39-39

Pinion shaft, adjusting


(Adjusting pinion shaft and hollow shaft)
Adjustment of the pinion shaft is only necessary
if the gear set, tapered roller bearing for the
pinion shaft, or the transmission housing has
been replaced table, Page 39
-37
.

Special tools and equipment

VW296 removal tool
VW385/1 measuring bar
VW385/3 centering disc (2x)
VW385/14 measuring rod
VW385/17 magnetic plate
VW385/30 master gauge-adjustable
VW385/33 end gauge
VW387 dial indicator holder
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VW401 thrust plate
VW407 punch
VW519 sleeve
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pinion shaft, ad
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39-40

VW792 installation arbor
3062 thrust pad
3182 sleeve
Torque gauge 0-600 Ncm (53 in. lb)
Dial indicator
Dial indicator extension 6.5 mm
Dial indicator extension 30 mm
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pinion shaft, ad
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yp
e=re
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