AUDI A4 1999 B5 / 1.G AFC Engine Cylinder Block Crankshaft And Flywheel Component Assembly Manual

13-21

Crankshaft axial and radial clearance,
checking


Orientation of crankshaft bearing caps
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.
Checking axial clearance
Main bearing cap -1- is at the oil pump end (front).Main bearing cap -4- is at the flywheel end (rear).

- Install dial indicator with holder VW 387 on oil pump and set indicator
against crankshaft counterweight.
- Press crankshaft against dial indicator by hand.
- Set dial gauge to zero.
- Press crankshaft away from dial indicator and read gauge.
Specifications:

New: 0.07-0.23 mm (0.0027-0.0091 in.)
Wear limit: 0.25 mm (0.0098 in.)
Pa
ge 21 of 32 C
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13-22

Checking radial clearance

Note:
Radial clearance is measured using Plastigage
.
Plastigage type
Color
Measuring range
PG-1 Green 0.025 - 0.076 mm
PR-1 Red 0.050 - 0.150 mm

- Remove crankshaft bearing cap.

- Clean bearing shell and crankshaft journal.

CAUTION!
Do NOT turn the crankshaft or allow it to rotate during the
measurement with Plastigage in place. -
Place Plastigage on crankshaft journal over entire width of bearing,
or in bearing shell (arrow). - Install crankshaft bearing cap with bearing shell and new bolts.
-
Tighten to 60 Nm (44 ft lb) plus1/2-turn 180 .
Pa
ge 22 of 32 C
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13-23

- Remove crankshaft bearing cap again.

-
Compare width of Plastigage with measuring scale. Specifications:

New: 0.018-0.045 mm (0.0007-0.0018 in.)
Wear limit: 0.10 mm (0.0039 in.)
Pa
ge 23 of 32 C
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ponent la
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13-24
Crankshaft dimensions

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)
Basic dimension (nominal) 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) 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) 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) 64.25 (2.530) 53.25 (2.096)
minimum size (from nominal) -0.042 (0.00165) -0.042 (0.00165)
Pa
ge 24 of 32 C
ylinder block, crankshaft and fl
ywheel, com
ponent la
yout
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13-25

Pistons and piston rings, checking and
installing


Note:
Before removing the pistons, mark their
installation positions clearly on the piston crowns
(as shown in illustration 13-860) using a
waterproof felt-tipped pen.

Piston installed position

CAUTION!
Do NOT scratch or scribe the piston surface. This surface has a
coating on it that must not be disturbed. - Arrow marking must point toward oil pump (front).
- Mark position clearly on piston crown with waterproof felt pen.

- Install piston using piston ring compressor.
Pa
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13-26

Checking pistons

- Measure piston approx. 10 mm (0.39 in.) from bottom of skirt, at right
angle (90 ) to piston pin. Maximum deviation from nominal dimension: 0.04 mm (0.0016 in.)

Checking and installing piston rings
"TOP" inscription must point toward piston crown Inner chamfer on plain ring must point toward piston crown Outer chamfer of stepped ring must point toward piston crown
Pa
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13-27


- Remove and install piston rings using ring expander as shown.

- Check piston ring clearance in groove.

New: 0.02-0.08 mm (0.001-0.003 in.)
Wear limit: 0.10 mm (0.004 in.)
Pa
ge 27 of 32 C
ylinder block, crankshaft and fl
ywheel, com
ponent la
yout
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13-28


- Check piston ring gap.
- Push piston ring into lower end of cylinder at right angle until approx.
15 mm (0.59 in.) from bottom edge. Piston ring
End gap
Wear limit
1 0.35 - 0.50 mm
(0.014 - 0.020 in.) 1.0 mm
(0.039 in.)
2 0.50 - 0.70 mm
(0.020 - 0.028 in.) 1.4 mm
(0.055 in.)
3 0.25 - 0.50 mm
(0.010 - 0.020 in.) 0.8 mm
(0.032 in.)
Pa
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ywheel, com
ponent la
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13-29

Checking cylinder bore

1 - Approx. 10 mm from top

2 - Center

3 - Approx. 10 mm from bottom

A - Across cylinder block (perpendicular to
crankshaft)

B - In line with cylinder block (parallel to
crankshaft)

CAUTION!
DO NOT have the cylinder block mounted to the assembly stand
while measuring the cylinder bores. The block is deformed by its
own weight under these conditions and this stress will result in false
measurements that are not accurate after the tension has been
relieved. - Measure diagonally at three points in transverse direction -A- and in
longitudinal direction -B-.

Use internal dial gauge 50-100 mm (2-4 in.)
Maximum deviation from nominal dimension: 0.08 mm (0.0031 in.)
Pa
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13-30

Piston and cylinder dimensions

Reconditioning
dimension Piston
diameter Cylinder
bore
diameter
Basic dimension 82.48 mm

(3.2472
in.) 82.51 mm
(3.2484 in.)
1st oversize 82.74 mm

(3.2575
in.) 82.76 mm
(3.2583 in.)
2nd oversize 82.98 mm

(3.2669
in.) 83.01 mm
(3.2681 in.)

Note:
Only pistons of the "basic dimension" size are
available from the Parts Department.
Pa
ge 30 of 32 C
ylinder block, crankshaft and fl
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ponent la
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yp
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