1999 SUBARU LEGACY Service Repair Manual

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.
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.
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2-3b[W5B2]SERVICE PROCEDURE
5. Cylinder Block

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) Check for cracks and damage visually.
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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[W5C1]2-3bSERVICE PROCEDURE
5. Cylinder Block

2. CYLINDER AND PISTON
1) The cylinder bore size is stamped on the cylin-
der block's front upper surface.
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: 99.505 Ð 99.515 mm (3.9175 Ð 3.9179
in)
B: 99.495 Ð 99.505 mm (3.9171 Ð 3.9175
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 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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2-3b[W5C2]SERVICE PROCEDURE
5. Cylinder Block

4) How to measure the outer diameter of each
piston
Measure the outer diameter of each piston at the
height shown in figure. (Thrust direction)
CAUTION:
Measurement should be performed at a tem-
perature of 20ÉC (68ÉF).
Piston grade point H:
37.0 mm (1.457 in)
Piston outer diameter:
Standard
A: 99.485 Ð 99.495 mm (3.9167 Ð 3.9171
in)
B: 99.475 Ð 99.485 mm (3.9163 Ð 3.9167
in)
0.25 mm (0.0098 in) oversize
99.725 Ð 99.735 mm (3.9262 Ð 3.9266 in)
0.50 mm (0.0197 in) oversize
99.975 Ð 99.985 mm (3.9360 Ð 3.9364 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 piston 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 0.010 mm (0.0002 Ð 0.0004 in)
Limit
0.020 mm (0.0008 in)
B2M1401
B2M0084A
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[W5C3]2-3bSERVICE PROCEDURE
5. Cylinder Block

4) Check circlip installation groove on the piston
for burr. If necessary, remove burr from the groove
so that piston pin can lightly move.
B2M0420A
5) Check piston pin circlip for distortion, cracks
and wear.
4. PISTON RING
1) If piston ring is broken, damaged, or worn, or if
its tension is insufficient, or when the piston is
replaced, replace piston ring with a new one of the
same size as the piston.
CAUTION:
IªRº is marked on the end of the top and sec-
ond rings. When installing the rings to the
piston, face this mark upward.
G2M0623
IThe oil ring is a combined ring consisting of
two rails and a spacer in between. When
installing, be careful to assemble correctly.
G2M0624
2) Squarely place piston ring and oil ring in
cylinder, and measure the piston ring gap with a
thickness gauge.
Unit: mm (in)
Standard Limit
Piston
ring gapTop ring0.20 Ð 0.35
(0.0079 Ð
0.0138)1.0 (0.039)
Second ring0.37 Ð 0.52
(0.0146 Ð
0.0205)1.0 (0.039)
Oil ring rail0.20 Ð 0.60
(0.0079 Ð
0.0236)1.5 (0.059)
G2M0174
3) Measure the clearance between piston ring and
piston ring groove with a thickness gauge.
CAUTION:
Before measuring the clearance, clean the pis-
ton ring groove and piston ring.
Unit: mm (in)
Standard Limit
Clearance
between
piston ring
and piston
ring grooveTop ring0.040 Ð
0.080
(0.0016
Ð0.0031)0.15 (0.0059)
Second ring0.030 Ð
0.070
(0.0012
Ð0.0028)0.15 (0.0059)
B2M1402A
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2-3b[W5C4]SERVICE PROCEDURE
5. Cylinder Block

5. CONNECTING ROD
1) Replace connecting rod, if the large or small
end thrust surface is damaged.
2) Check for bend or twist using a connecting rod
aligner. Replace connecting rod if the bend or twist
exceeds the limit.
Limit of bend or twist per 100 mm (3.94 in) in
length:
0.10 mm (0.0039 in)
B2M1184A
3) Install connecting rod fitted with bearing to
crankshaft and measure the side clearance (thrust
clearance). Replace connecting rod if the side
clearance exceeds the specified limit.
Connecting rod side clearance:
Standard
0.070 Ð 0.330 mm (0.0028 Ð 0.0130 in)
Limit
0.4 mm (0.016 in)
G2M0176
4) Inspect connecting rod bearing for scar,
peeling, seizure, melting, wear, etc.5) Measure the oil clearance on individual con-
necting rod bearings by means of plastigauge. If
any oil clearance is not within specification, replace
the defective bearing with a new one of standard
size or undersize as necessary. (See the table.)
Connecting rod oil clearance:
Standard
0.010 Ð 0.038 mm (0.0004 Ð 0.0015 in)
Limit
0.05 mm (0.0020 in)
Unit: mm (in)
BearingBearing size
(Thickness at cen-
ter)Outer diameter of
crank pin
Standard1.492 Ð 1.501
(0.0587 Ð
0.0591)51.984 Ð 52.000
(2.0466 Ð
2.0472)
0.03 (0.0012)
undersize1.510 Ð 1.513
(0.0594 Ð
0.0596)51.954 Ð 51.970
(2.0454 Ð
2.0461)
0.05 (0.0020)
undersize1.520 Ð 1.523
(0.0598 Ð
0.0600)51.934 Ð 51.950
(2.0446 Ð
2.0453)
0.25 (0.0098)
undersize1.620 Ð 1.623
(0.0638 Ð
0.0639)51.734 Ð 51.750
(2.0368 Ð
2.0374)
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[W5C5]2-3bSERVICE PROCEDURE
5. Cylinder Block

6) Inspect bushing at connecting rod small end,
and replace if worn or damaged. Also measure the
piston pin clearance at the connecting rod small
end.
Clearance between piston pin and bushing:
Standard
0 Ð 0.022 mm (0 Ð 0.0009 in)
Limit
0.030 mm (0.0012 in)
B2M0085
B2M0084A
7) Replacement procedure is as follows.
(1) Remove bushing from connecting rod with
ST and press.
(2) Press bushing with ST after applying oil on
the periphery of bushing.
ST 499037100 CONNECTING ROD BUSH-
ING REMOVER AND
INSTALLER
G2M0177
(3) Make two 3 mm (0.12 in) holes in bushing.
Ream the inside of bushing.
(4) After completion of reaming, clean bushing
to remove chips.
6. CRANKSHAFT AND CRANKSHAFT
BEARING
1) Clean crankshaft completely and check for
cracks by means of red lead check etc., and
replace if defective.
2) Measure the crankshaft bend, and correct or
replace if it exceeds the limit.
CAUTION:
If a suitable V-block is not available, install #1
and #5 crankshaft bearing on cylinder block,
position crankshaft on these bearings and
measure crankshaft bend using a dial gauge.
Crankshaft bend limit:
0.035 mm (0.0014 in)
G2M0178
3) Inspect the crank journal and crank pin for
wear. If not to specifications, replace bearing with
an undersize one, and replace or recondition
crankshaft as necessary. When grinding crank
journal or crank pin, finish them to the specified
dimensions according to the undersize bearing to
be used.
Crank pin and crank journal:
Out-of-roundness
0.020 mm (0.0008 in) or less
Taper limit
0.07 mm (0.0028 in)
Grinding limit
0.25 mm (0.0098 in)
G2M0179
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2-3b[W5C6]SERVICE PROCEDURE
5. Cylinder Block

Unit: mm (in)
Crank journal diameter
Crank pin diameter
#1, #5 #2, #3, #4
StandardJournal O.D.59.992 Ð 60.008
(2.3619 Ð 2.3625)59.992 Ð 60.008
(2.3619 Ð 2.3625)51.984 Ð 52.000
(2.0466 Ð 2.0472)
Bearing size
(Thickness at
center)1.998 Ð 2.011
(0.0787 Ð 0.0792)2.000 Ð 2.013
(0.0787 Ð 0.0793)1.492 Ð 1.501
(0.0587 Ð 0.0591)
0.03 (0.0012)
undersizeJournal O.D.59.962 Ð 59.978
(2.3607 Ð 2.3613)59.962 Ð 59.978
(2.3607 Ð 2.3613)51.954 Ð 51.970
(2.0454 Ð 2.0461)
Bearing size
(Thickness at
center)2.017 Ð 2.020
(0.0794 Ð 0.0795)2.019 Ð 2.022
(0.0795 Ð 0.0796)1.510 Ð 1.513
(0.0594 Ð 0.0596)
0.05 (0.0020)
undersizeJournal O.D.59.942Ð 59.958
(2.3599 Ð 2.3605)59.942 Ð 59.958
(2.3599 Ð 2.3605)51.934 Ð 51.950
(2.0446 Ð 2.0453)
Bearing size
(Thickness at
center)2.027 Ð 2.030
(0.0798 Ð 0.0799)2.029 Ð 2.032
(0.0799 Ð 0.0800)1.520 Ð 1.523
(0.0598 Ð 0.0600)
0.25 (0.0098)
undersizeJournal O.D.59.742 Ð 59.758
(2.3520 Ð 2.3527)59.742 Ð 59.758
(2.3520 Ð 2.3527)51.734 Ð 51.750
(2.0368 Ð 2.0374)
Bearing size
(Thickness at
center)2.127 Ð 2.130
(0.0837 Ð 0.0839)2.129 Ð 2.132
(0.0838 Ð 0.0839)1.620 Ð 1.623
(0.0638 Ð 0.0639)
O.D. ... Outer Diameter
4) Measure the thrust clearance of crankshaft at
center bearing. If the clearance exceeds the limit,
replace bearing.
Crankshaft thrust clearance:
Standard
0.030 Ð 0.115 mm (0.0012 Ð 0.0045 in)
Limit
0.25 mm (0.0098 in)
G2M0180
5) Inspect individual crankshaft bearings for signs
of flaking, seizure, melting, and wear.
6) Measure the oil clearance on each crankshaft
bearing by means of plastigauge. If the measure-
ment is not within the specification, replace defec-
tive bearing with an undersize one, and replace or
recondition crankshaft as necessary.
Unit: mm (in)
Crankshaft oil clearance
Standard#1, #50.003 Ð 0.030
(0.0001 Ð
0.0012)
#2, #3, #40.010 Ð 0.033
(0.0004 Ð
0.0013)
Limit#1, #3, #5 0.040 (0.0016)
#2, #4 0.045 (0.0018)
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5. Cylinder Block