1999 AUDI A6 01E Transmission Final Drive Ring Gear Adjustment Workshop Manual

39-59

Measuring backlash
(Position of ring gear in transmission housing)

Drive pinion with shims "S3" and "S4"
installed

- Install differential.

- Turn differential 5 turns in each direction to
settle tapered roller bearings.

- Secure dial gauge retainer VW 387 onto housing.
- Insert adjustment device VW 521/4 and VW 521/8 for ring gear.
- Fit dial gauge with dial gauge extension VW 382/10 (6 mm flat).
- Set measuring lever VW 388 to dimension a = 79 mm.
- Determine play between the teeth flanks as follows:
- Turn ring gear until it makes contact with a tooth flank (end of
backlash travel).
- Set dial gauge to "0" with 2 mm preload.
- Turn ring gear back until lying against an opposite tooth flank
(backlash).
Pa
ge 9 of 15 Rin
g gear, ad
justin
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11/19/2002 htt
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yp
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39-60

- Read off backlash and note value.

-
Turn ring gear through 90 and repeat
measurements a further 3 times.
Note:
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

- Add the four measurements together and divide
by four.

Example:

1st measurement 0.49 mm
+ 2nd measurement 0.48 mm
+ 3rd measurement 0.50 mm
+ 4th measurement 0.49 mm
= Sum of measured values 1.96 mm

Result: The average backlash is 1.96 4 =
0.49 mm
Pa
ge 10 of 15 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.TM03.39.8

39-61

Determining thickness of shim"S2"

Formula:
"S2"
=
"S2*" - backlash + lift

Example:

Inserted shim "S2*" 1.20 mm
- Average backlash 0.49 mm
+ Lift (constant) 0.15 mm
= Thickness of shim "S2" 0.86 mm

- Determine shim(s) from table.

Parts catalog
The following shims are available for "S2"

Shim thickness (mm)
1)
0.45 0.65 0.85
0.50 0.70 0.90
0.55 0.75
0.60 0.80
Pa
ge 11 of 15 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.TM03.39.8

1) Using the shim tolerance variations it is
possible to find the exact shim thickness
required, insert two shims if necessary.
Pa
ge 12 of 15 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.TM03.39.8

39-62

Determining thickness of shim "S1"

Formula:
"S1"
=
"S
total
" - "S2"

Example:

Total shim thickness "S
total
" for "S1"
+ "S2" 2.07
mm
- Thickness of shim "S2" 0.86
mm
= Thickness of shim "S1" 1.21
mm

- Determine shim(s) from table.

Parts catalog

The following shims are available for "S1"

Shim thickness (mm)
1)
0.45 0.65 0.85
0.50 0.70 0.90
0.55 0.75
Pa
ge 13 of 15 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.TM03.39.8

0.60 0.80

1) Using the shim tolerance variations it is
possible to find the exact shim thickness
required, insert two shims if necessary.
Pa
ge 14 of 15 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.TM03.39.8

39-63


Performing check measurement
Note: - After installing shims "S1" and "S2," turn differential 5 turns in both
directions so that the tapered roller bearings settle.
- Measure backlash four times on circumference.
Specifications: 0.12-0.22 mm
If the backlash lies outside the tolerances, the adjustments must be
repeated. But the total shim thickness "S
total
" must remain the same.
The individual measurements must not differ by more than 0.06 mm
from each other.
Pa
ge 15 of 15 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.TM03.39.8