AUDI A8 2001 D2 / 1.G 01V Transmission Drive Pinion And Ring Gear Adjust Workshop Manual

39-166


Drive pinion and ring gear,
adjusting

General notes:

Drive pinion and ring gear must be very
carefully adjusted to ensure long service life
and smooth running. At the factory, drive pinion
and ring gear are adjusted relative to each
other to ensure smooth running and low noise
in both directions. The location for the
smoothest running is determined by moving
drive pinion axially whereby ring gear is moved
far enough out of the backlash-free position so
that the backlash is within specified tolerances.
The goal of the adjustment is to reproduce the
setting for the quietest possible running, as
obtained on the test machine during production.
The deviation, or tolerance "r" which is based
on the master gauge "R0" is measured for the
final drive sets supplied as replacement parts
and marked on the outer circumference of the
ring gear. Every drive pinion set - drive pinion
and ring gear - may only be replaced together.
Follow general repair notes for tapered roller
bearings and shims.

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Make sure that all installation and measurement
procedures are performed with the utmost care
and cleanliness to ensure a successful result.
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Gear set, adjusting and marking

1 -
Identification "0937" means the Oerlikon
gear set with a ratio of 37: 9.
2 -
Pairing number (312) of gear set.
3 -
Dimension "r" is based on the master
gauge used on the test bench during
production. Dimension "r" is always given
in 1/100 mm. Example: "25" means r =
0.25 mm
Ro - Length of test machine master gauge
used "Ro".
Ro - ring gear = 57.50 mm
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R - Actual dimension between ring gear
axis and face of drive pinion in position
of quietest running for this gear set R =
Ro + r
Vo - Hypoid offset
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39-169

Gear set, adjustment sequence

If drive pinion and gear ring have to be adjusted,
the following sequence is recommended for
maximum efficiency:

1.) Determine total shim thickness "Stot"for S1 +
S2 for the specified pre-tension of tapered
roller bearings for differential.
2.) Determine total shim thickness "S3" so that
the drive pinion is installed in the same
location as on the test machine during
production.
3.) Distribute total shim thickness Stotal S1 +
S2, so that the specified backlash between
ring gear and drive pinion is maintained.

Note:
Overview of components and adjustment shims
page 39
-171
.
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39-170
Adjustment overview

Note:
When working on transmission, drive pinion or gear set only need to be adjusted if components were replaced which directly
influence the final drive. Note the follow table to prevent unnecessary adjustments:

Component to be adjusted:

Component replaced:

Ring gear
"S1"+"S2"
1)

page 39
-186

Drive pinion
"S3"
1)
via deviation "r"
page 39-177

Backlash
Checking

page 39
-192

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
Gear set
2)
X X X
Cover for final drive X X
1) Adjustment shims; Installed position page 39
-171

2) Drive pinion and ring gear; only replace together as a set
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39-171


Shim location

Note:
Adjustment overview when replacing individual
components of differential page 39
-170
.
S1 - Adjustment shim for ring gear in final
drive cover
S2 - Adjustment shim for ring gear in final
drive housing
S3 - Adjustment shim for ring gear in final
drive housing
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39-172


Special tools and equipment

VW382/10 extension pin
VW385/1 measuring bar
VW385/2 centering disc
VW385/3 plastic piece
VW385/14 measuring rod
VW385/15 extension pin
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VW385/17 magnetic plate
VW385/30 master gauge-adjustable
VW385/33 end gauge
VW387 dial gauge holder
VW388 measuring lever
VW401 thrust plate
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pinion and rin
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39-174



VW402 thrust plate
VW408A punch
VW457 support channels
VW521/4 locking sleeve for ring gear
VW521/8 bushing for ring gear
VW540 holding fixture
Pa
ge 10 of 38 Drive
pinion and rin
g gear, ad
justin
g
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yp
e=re
pair&id=AUDI.B5.AT01.39.15