1997 AUDI A4 01A Transmission Total Shim Thickness Workshop Manual

39-61

Determining thickness of shim "S1*"

Notes:

The preliminary adjustment 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 thickness Stotal for S1 +
S2
2.12
mm
- Inserted shim(s) S2* 1.20
mm
= Thickness of shim S1* 0.92
mm
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39-62

Measuring friction torque

Notes:

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 friction torque measurement. The
bearings have already been treated with a
special oil by the manufacturer.
Pinion shaft removed

Friction torque specifications:
Note: - Install torque gauge 0-600 Ncm (53 in. lb) -A- onto differential.
B - Socket
- Read friction torque.
New bearings
Used bearings
150-350 Ncm (13-31 in. lb) 30-60 Ncm (3-5 in. lb)
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For a readjustment of the final drive gear set (pinion shaft and ring gear),
the pinion shaft adjustment should now be checked Page 39
-39
.
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39-63

Measuring backlash
Position of ring gear in transmission housing

Pinion shaft with shims S3* and S4* installed

- Install differential.

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

- Secure VW387 dial indicator holder onto housing.
- Attach VW521/4 locking sleeve and VW521/12.
- Install dial indicator and VW382/10 extension pin (6 mm flat).
- Adjust VW388 measuring lever to dimension -a-:
Distance -a-: 67 mm (2.637 in.) for 170 mm (6.693 in.) diameter ring
gear.
- 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 2 mm preload.
- Turn ring gear back against opposite tooth flank (backlash).
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39-64

- Recording (backlash) indicated on gauge.

-
Turn ring gear 90 further each time and
repeat measurement 3 times.
Notes:

Determining average backlash
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 gear set
Install VW386A clamping piece if the pinion shaft rotates when the
differential is turned. This way the exact backlash can be measured. Loosen clamping piece in order to turn the ring gear further.
- Add four measured values together and divide by four.
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
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itself is not correct. Check installation, replace final drive gear set if
necessary.
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39-65

Determining thickness of shim S2

Formula:
S2 = S2* - backlash + lift

Example:

Inserted shim S2* 1.20 mm
- Average backlash 0.29 mm
+ Lift (constant value) 0.15 mm
= Thickness of shim S2 1.06 mm

- Determine shim(s) according to table. Part
numbers 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
1) By using shim tolerances it is possible to find
exact shim thickness required, insert two shims if
necessary.
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pair&id=AUDI.B5.TM02.39.7

39-66

Determining thickness of shim "S1"

Formula:
S1 = Stotal - S2

Example:

Total shim thickness Stotal for S1 +
S2 2.12
mm
- Thickness of shim S2 1.06
mm
= Thickness of shim S1 1.06
mm

- Determine shim(s) according to table. Part
numbers 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
0.60 0.80
1) By using shim tolerances it is possible to find
the exact shim thickness required, insert two
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pair&id=AUDI.B5.TM02.39.7