AUDI A8 1998 D2 / 1.G AHA ATQ Engines Cylinder Block Crankshaft And Flywheel Component Owner's Manual

13-22

Dual-mass flywheel or driveplate,
removing and installing, installation
dimensions


Dual-mass flywheel

Note:
A pilot needle bearing is in the dual-mass flywheel and must be inserted
when dual-mass flywheel is replaced.
Note:
Always replace dual-mass flywheel mounting bolts. - With crankshaft at Top Dead Center (TDC), install 3242 crankshaft
holder.
- Mark position of dual-mass flywheel and engine housing (arrows).
- Remove bolts and replace.Component
Tightening torque
Dual-mass flywheel to crankshaft
60 Nm (44 ft lb) + 180 Clutch to dual-mass flywheel 20 Nm (15 ft lb)
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13-23

Driveplate

- Hold crankshaft in position using 3242
crankshaft holder page 13
-12
.

- Mark hole pattern of driveplate, shim -1- and
washer -2- to crankshaft.

- Mark positions of shim -1- and washer -2-
(behind driveplate).

CAUTION!
Part numbers are listed here for reference only. Always check with
your Parts department for the latest information.
Notes: - Install driveplate with washer -2- (Part No. 035 105 303 A) and shim -1-
3.0 mm (Part No. 054 105 301) or 4.0 mm (Part No. 054 105 202).
Short engines and exchange engines are supplied without a bushing
in the crankshaft. Always install a new bushing before installing the
driveplate. Remove bushing using 21/1 Kukko puller and 21/2 Kukko support.Always replace driveplate mounting bolts.
Component
Tightening torque
Driveplate to crankshaft
30 Nm (22 ft lb) + 90
Pa
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ylinder block, crankshaft and fl
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13-24


Note:
Before installing the engine, make sure the engine to transmission
centering sleeves are installed in the engine flange. - Measure distance -a- at three places and calculate average.
Distance -a-: approx. 12.3 mm.
- If necessary, install different shim.
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11/21/2002 htt
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13-25

Crankshaft axial and radial clearance,
measuring


Axial clearance

CAUTION!

Bearing shells must be reinstalled in their
original location and orientation. Always label
the bearing shells according to their installed
position before removing. Never interchange
used bearing shells.

- Attach dial indicator together with VW387 dial indicator holder to oil
pump and set indicator against crankshaft counterweight.
- Press crankshaft against dial indicator by hand and set indicator to
zero.
- Press crankshaft away from dial indicator.
- Read gauge.
Clearance when new
Wear limit
0.07-0.23 mm (0.0028-0.0091 in.) 0.25 mm (0.0098 in.)
Pa
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11/21/2002 htt
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13-26

Radial clearance

-
Measure radial clearance using Plastigage .
- Read clearance.

Clearance when new
Wear limit
0.018-0.045 mm (0.0007-
0.0018 in.) 0.10 mm (0.0039
in.)

CAUTION!

DO NOT turn the crankshaft or allow it to
rotate while measuring with Plastigage in
place.
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11/21/2002 htt
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13-27

Crankshaft bearing cap, installing


Bearing -1- is installed on the oil pump side of the cylinder block, and
bearing -4- on the dual-mass flywheel side of the cylinder block.
Pa
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13-28
Crankshaft dimensions

Engine codes AHA, ATQ
Reconditioning dimension
Crankshaft journal diameter mm (in.)
Connecting rod journal diameter mm (in.)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
Standard (nominal dimension) 65.00 (2.559) 54.00 (2.126)
minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
1st undersize (nominal dimension) 64.75 (2.549) 53.75 (2.116)
minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
2nd undersize (nominal dimension) 64.50 (2.539) 53.50 (2.106)
minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
maximum size (from nominal) -0.022 (0.00087) -0.022 (0.00087)
3rd undersize (nominal dimension) 64.25 (2.530) 53.25 (2.096)
minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
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11/21/2002 htt
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13-29

Pistons and piston rings


Pistons

Installation position: arrow on piston crown must point in driving direction.
CAUTION!
DO NOT scratch or scribe on piston crown. The surface has a
coating that must not be damaged.
Checking piston diameter - Mark cylinder number on piston crown using waterproof felt pen.

- Measure pistons approx. 10 mm (3/8 in.) from bottom edge at right
angle (90 ) to piston pin. Deviation from nominal size: 0.04 mm (0.0016 in.).
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13-30

Piston and cylinder bore dimensions

Reconditioning
dimension Piston diameter
Basic dimension 82.48 mm (3.247
in.)
1st oversize 82.74 mm (3.257
in.)

Checking piston ring side clearance
Clearance when new
Wear limit
0.02-0.08 mm (0.0008-0.0031 in.) 0.10 mm (0.004 in.)
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13-31


Checking piston ring end gap
Engine codes AHA, ATQ - Insert ring at right angle from top and slide down into lower cylinder
opening until approx. 15 mm from lower edge of cylinder. Piston ring
End gap, new mm. (in.)
Wear limit mm.
(in.)
1
(compression) 0.35-0.50 mm (0.014-0.020
in.) 1.0 mm (0.039 in.)
2
(compression) 0.50-0.70 mm (0.020-0.028
in.) 1.4 mm (0.043 in.)
3 (oil scraper) 0.25-0.50 mm (0.010-0.020
in.) 0.8 mm (0.031 in.)
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ylinder block, crankshaft and fl
ywheel, servicin
g
11/21/2002 htt
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yp
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pair&id=AUDI.B5.GE03.13.2