1997 AUDI A4 differential

39-57

Measuring friction torque (check
measurement)

Notes:

Tapered roller bearings for differential are low-
friction. Measurement of friction torque only has
a limited use as a check. Correct adjustment is
only possible by determining the total shim
thickness "Stotal."
Do not lubricate new tapered roller bearings for
measuring friction torque. The bearings have
already been treated by a special oil by the
manufacturer.
Pinion shaft removed

Friction torque specified values:
Note: - Install torque gauge 0-600 Ncm -A- on differential.
- Read friction torque.New bearings
Used bearings
200 - 350 Ncm 30 - 60 Ncm
Pa
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g gear, ad
justin
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11/19/2002 htt
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yp
e=re
pair&id=AUDI.B5.TM01.39.5

39-58

Measuring backlash
(Position of ring gear in transmission housing)

Pinion shaft with shims "S3*" and "S4*"
installed

- Install differential.

- Turn differential 5 rotations in each direction to
seat tapered roller bearing.

- Secure VW387 dial gauge holder on housing.
- Install VW521/4 locking sleeve and VW521/8 bushing (for
transmissions without polygon bearing) or VW521/12 (for transmissions
with polygon bearings).
- Install dial indicator with VW382/10 extension pin, 6 mm.
- Set VW388 measuring lever to dimension "a:"Dimension "a"
Ring gear diameter
67 mm 170 mm
72 mm 180 mm
Pa
ge 37 of 43 Pinion shaft and rin
g gear, ad
justin
g
11/19/2002 htt
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yp
e=re
pair&id=AUDI.B5.TM01.39.5

39-59

- Determine play between teeth flanks as
follows:

- Turn ring gear until it contacts a tooth flank
(end of backlash travel).

- Set dial indicator to 0 with 2 mm preload.

- Turn ring gear back until it contacts opposite
tooth flank (backlash).

- Read backlash and note.

-
Turn ring gear another 90 and repeat
measurement 3 times.
Notes:

If pinion shaft turns when turning differential, install 3177 clamp -A- so
that an exact backlash measurement can be made. Loosen clamping piece to turn the ring gear further.Differential must be installed with cutout for differential bevel gears
facing pinion shaft.
-
If 3177 clamp is installed, install differential 180 to final position and
repeat measurements.
Pa
ge 38 of 43 Pinion shaft 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.TM01.39.5

39-63


Checking measurement
Note:
For transmissions without polygon bearing, use VW521/8 bushing instead
of VW521/12 shown.
Notes: - After installing shims "S1" and "S2," turn differential 5 rotations in each
direction to seat tapered roller bearings.
- Measure backlash 4 times on circumference.
Specification: 0.12-0.22 mm
If backlash lies outside tolerance, repeat adjustments. Do not change
total shim thickness "Stotal." The individual measurements must not vary more than 0.06 mm from
each other.
Pa
ge 43 of 43 Pinion shaft 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.TM01.39.5