1999 SUBARU LEGACY Service Repair Manual

6. Cylinder Block
A: REMOVAL
1. RELATED PARTS
1) Remove timing belt, camshaft sprockets and
related parts.

2) Remove cylinder heads. [W5A0].>
3) Remove water pipe.
B2M2638
51
[W6A1]2-3aSERVICE PROCEDURE
6. Cylinder Block

2. OIL PUMP AND WATER PUMP
B2M1767A
(1) Clutch housing cover (MT
vehicles only)
(2) Flywheel (MT vehicles only)
(3) Drive plate (AT vehicles only)(4) Oil separator cover
(5) Water by-pass pipe
(6) Water pump
(7) Oil pump(8) Oil pan
(9) Oil strainer
(10) Baffle plate
(11) Oil filter
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2-3a[W6A2]SERVICE PROCEDURE
6. Cylinder Block

1) Remove clutch housing cover (MT vehicles
only).
2) Remove flywheel (MT vehicles only) or drive
plate (AT vehicles only).
Using ST, lock crankshaft.
ST 498497100 CRANKSHAFT STOPPER
G2M0776
B2M0706A
3) Remove oil separator cover.
4) Remove water by-pass pipe for heater.
5) Remove water pump.
6) Remove oil pump from cylinder block.
Use a flat-bladed screwdriver as shown in figure
when removing oil pump.
CAUTION:
Be careful not to scratch the mating surface of
cylinder block and oil pump.
G2M0162
7) Removal of oil pan
(1) Turn cylinder block with #2 and #4 piston
sides facing upward.
(2) Remove bolts which secure oil pan to cylin-
der block.
(3) Insert a oil pan cutter blade between cylin-
der block-to-oil pan clearance and remove oil
pan.
CAUTION:
Do not use a screwdriver or similar tool in
place of oil pan cutter.
G2M0163
8) Remove oil strainer stay.
9) Remove oil strainer.
10) Remove baffle plate.
11) Remove oil filter using ST.
ST 498187300 OIL FILTER WRENCH
B2M2611A
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[W6A2]2-3aSERVICE PROCEDURE
6. Cylinder Block

B: DISASSEMBLY
1. PISTON PIN AND CYLINDER BLOCK CONNECTING BOLT
B2M1180A
(1) Service hole plug
(2) Gasket(3) Circlip
(4) Piston pin(5) Service hole cover
1) Remove service hole cover and service hole
plugs using hexagon wrench [14 mm (0.55 in)].
B2M2620
2) Rotate crankshaft to bring #1 and #2 pistons to
bottom dead center position, then remove piston
circlip through service hole of #1 and #2 cylinders.
G2M0165
54
2-3a[W6B1]SERVICE PROCEDURE
6. Cylinder Block

3) Draw out piston pin from #1 and #2 pistons
using ST.
ST 499097700 PISTON PIN REMOVER
CAUTION:
Be careful not to confuse original combination
of piston, piston pin and cylinder.
G2M0166
4) Similarly remove piston pins from #3 and #4
pistons.
5) Remove bolts which connect cylinder block on
the side of #2 and #4 cylinders.
6) Back off bolts which connect cylinder block on
the side of #1 and #3 cylinders two or three turns.
2. CYLINDER BLOCK
B2M2408A
(1) Cylinder block
(2) Rear oil seal(3) Crankshaft
(4) Crankshaft bearing(5) Piston
1) Set up cylinder block so that #1 and #3 cylin-
ders are on the upper side, then remove cylinder
block connecting bolts.
2) Separate left-hand and right-hand cylinder
blocks.CAUTION:
When separating cylinder block, do not allow
the connecting rod to fall and damage the cyl-
inder block.
3) Remove rear oil seal.
55
[W6B2]2-3aSERVICE PROCEDURE
6. Cylinder Block

4) Remove crankshaft together with connecting
rod.
5) Remove crankshaft bearings from cylinder
block using hammer handle.
CAUTION:
Do not confuse combination of crankshaft
bearings. Press bearing at the end opposite to
locking lip.6) Draw out each piston from cylinder block using
wooden bar or hammer handle.
CAUTION:
Do not confuse combination of piston and cyl-
inder.
3. CRANKSHAFT AND PISTON
B2M1320I
(1) Connecting rod cap
(2) Connecting rod bearing(3) Top ring
(4) Second ring(5) Oil ring
(6) Circlip
1) Remove connecting rod cap.
2) Remove connecting rod bearing.
CAUTION:
Arrange removed connecting rod, connecting
rod cap and bearing in order to prevent confu-
sion.
3) Remove piston rings using the piston ring
expander.
4) Remove the oil ring by hand.
CAUTION:
Arrange the removed piston rings in good
order to prevent confusion.
5) Remove circlip.
C: INSPECTION
1. CYLINDER BLOCK
1) Visually check for cracks and damage.
Especially, inspect important parts by means of red
lead check.
2) Check the oil passages for clogging.3) Inspect crankcase surface that mates with cyl-
inder head for warping by using a straight edge,
and correct by grinding if necessary.
Warping limit:
0.05 mm (0.0020 in)
Grinding limit:
0.1 mm (0.004 in)
Standard height of cylinder block:
201.0 mm (7.91 in)
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2-3a[W6B3]SERVICE PROCEDURE
6. Cylinder Block

2. CYLINDER AND PISTON
1) The cylinder bore size is stamped on the cylin-
der block's front upper surface.
CAUTION:
Measurement should be performed at a tem-
perature 20ÉC (68ÉF).
NOTE:
Standard sized pistons are classified into two
grades, ªAº and ªBº. These grades should be used
as a guide line in selecting a standard piston.
Standard diameter:
A: 96.905 Ð 96.915 mm (3.8151 Ð 3.8155
in)
B: 96.895 Ð 96.905 mm (3.8148 Ð 3.8151
in)
H2M1732A
2) How to measure the inner diameter of each
cylinder
Measure the inner diameter of each cylinder in
both the thrust and piston pin directions at the
heights shown in the figure, using a cylinder bore
gauge.
CAUTION:
Measurement should be performed at a tem-
perature 20ÉC (68ÉF).
Taper:
Standard
0.015 mm (0.0006 in)
Limit
0.050 mm (0.0020 in)
Out-of-roundness:
Standard
0.010 mm (0.0004 in)
Limit
0.050 mm (0.0020 in)
G2M0170
3) When piston is to be replaced due to general or
cylinder wear, determine a suitable sized piston by
measuring the piston clearance.
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[W6C2]2-3aSERVICE PROCEDURE
6. Cylinder Block

4) How to measure the outer diameter of each
piston
Measure the outer diameter of each piston at the
height shown in the figure. (Thrust direction)
CAUTION:
Measurement should be performed at a tem-
perature of 20ÉC (68ÉF).
Piston grade point H:
40.0 mm (1.575 in)
Piston outer diameter:
Standard
A: 96.885 Ð 96.895 mm (3.8144 Ð 3.8148
in)
B: 96.875 Ð 96.885 mm (3.8140 Ð 3.8144
in)
0.25 mm (0.0098 in) oversize
97.125 Ð 97.135 mm (3.8238 Ð 3.8242 in)
0.50 mm (0.0197 in) oversize
97.375 Ð 97.385 mm (3.8337 Ð 3.8340 in)
B2M1305A
5) Calculate the clearance between cylinder and
piston.
CAUTION:
Measurement should be performed at a tem-
perature of 20ÉC (68ÉF).
Cylinder to piston clearance at 20ÉC (68ÉF):
Standard
0.010 Ð 0.030 mm (0.0004 Ð 0.0012 in)
Limit
0.050 mm (0.0020 in)
6) Boring and honing
(1) If the value of taper, out-of-roundness, or
cylinder- to-piston clearance measured exceeds
the specified limit or if there is any damage on
the cylinder wall, rebore it to use an oversize
piston.
CAUTION:
When any of the cylinders needs reboring, all
other cylinders must be bored at the same
time, and use oversize pistons. Do not perform
boring on one cylinder only, nor use an over-
size piston for one cylinder only.(2) If the cylinder inner diameter exceeds the
limit after boring and honing, replace the crank-
case.
CAUTION:
Immediately after reboring, the cylinder diam-
eter may differ from its real diameter due to
temperature rise. Thus, pay attention to this
when measuring the cylinder diameter.
Limit of cylinder enlarging (boring):
0.5 mm (0.020 in)
3. PISTON AND PISTON PIN
1) Check pistons and piston pins for damage,
cracks, and wear and the piston ring grooves for
wear and damage. Replace if defective.
2) Measure the piston-to-cylinder clearance at
each cylinder. If any of the
clearances is not to specification, replace the pis-
ton or bore the cylinder to use an oversize piston.
3) Make sure that piston pin can be inserted into
the piston pin hole with a thumb at 20ÉC (68ÉF).
Replace if defective.
Standard clearance between piston pin and
hole in piston:
Standard
0.004 Ð 0.008 mm (0.0002 Ð 0.0003 in)
Limit
0.020 mm (0.0008 in)
B2M1401
B2M0084A
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2-3a[W6C3]SERVICE PROCEDURE
6. Cylinder Block