SUBARU LEGACY 1997 Service Repair Manual

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 cylin-
der only, nor use an oversize piston for one cylinder
only.
(2) If the cylinder inner diameter exceeds the limit after
boring and honing, replace the crankcase.
CAUTION:
Immediately after reboring, the cylinder diameter may
differ from its real diameter due to temperature rise.
Thus, pay attention to this when measuring the cylin-
der 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 cylin-
der as instructed in 2. CYLINDER AND PISTON 2-3
[W7C2]. If any of the clearances is not to specification,
replace the piston or bore the cylinder to use an oversize
piston.
B2M0083
3) Make sure that piston pin can be inserted into the pis-
ton pin hole with a thumb at 20°C (68°F). Replace if defec-
tive.
Standard clearance between piston pin and hole in
piston:
Standard
0.004—0.010 mm (0.0002—0.0004 in)
Limit
0.020 mm (0.0008 in)
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7. Cylinder Block

B2M0084A
B2M0420A
4) Check circlip installation groove on the piston for burr.
If necessary, remove burr from the groove so that piston
pin can lightly move.
5) Check piston pin circlip for distortion, cracks and wear.
G2M0623
4. PISTON RING
1) If piston ring is broken, damaged, or worn, or if its ten-
sion is insufficient, or when the piston is replaced, replace
piston ring with a new one of the same size as the piston.
CAUTION:
“R”is marked on the end of the top and second
rings. When installing the rings to the piston, face this
mark upward.
G2M0624
The oil ring is a combined ring consisting of two
rails and a spacer in between. When installing, be care-
ful to assemble correctly.
G2M0174
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—0.35
(0.0079—0.0138)1.0 (0.039)
Second ring0.20—0.50
(0.0079—0.0197)1.0 (0.039)
Oil ring rail0.20—0.70
(0.0079—0.0276)1.5 (0.059)
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7. Cylinder Block

G2M0175
3) Measure the clearance between piston ring and piston
ring groove with a thickness gauge.
CAUTION:
Before measuring the clearance, clean the piston ring
groove and piston ring.
Unit: mm (in)
Standard Limit
Clearance
between piston
ring and piston
ring grooveTop ring0.040—0.080
(0.0016—
0.0031)0.15 (0.0059)
Second ring0.030—0.070
(0.0012—
0.0028)0.15 (0.0059)
5. CONNECTING ROD
1) Replace connecting rod, if the large or small end thrust
surface is damaged.
G2M0196
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)


1Thickness gauge


2Connecting rod
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7. Cylinder Block

G2M0176
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—0.330 mm (0.0028—0.0130 in)
Limit
0.4 mm (0.016 in)
4) Inspect connecting rod bearing for scar, peeling,
seizure, melting, wear, etc.
5) Measure the oil clearance on individual connecting 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 below.)
Connecting rod oil clearance:
Standard
0.015—0.045 mm (0.0006—0.0018 in)
Limit
0.05 mm (0.0020 in)
Unit: mm (in)
BearingBearing size
(Thickness at center)Outer diameter of
crank pin
Standard1.492—1.501
(0.0587—0.0591)51.984—52.000
(2.0466—2.0472)
0.03 (0.0012)
undersize1.510—1.513
(0.0594—0.0596)51.954—51.970
(2.0454—2.0461)
0.05 (0.0020)
undersize1.520—1.523
(0.0598—0.0600)51.934—51.950
(2.0446—2.0453)
0.25 (0.0098)
undersize1.620—1.623
(0.0638—0.0639)51.734—51.750
(2.0368—2.0374)
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B2M0085
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—0.022 mm (0—0.0009 in)
Limit
0.030 mm (0.0012 in)
B2M0084A
G2M0177
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 BUSHING
REMOVER AND INSTALLER
(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.
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7. Cylinder Block

G2M0178
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 crank-
shaft on these bearings and measure crankshaft bend
using a dial gauge.
Crankshaft bend limit:
0.035 mm (0.0014 in)
G2M0179
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 speci-
fied dimensions according to the undersize bearing to be
used.
Crank pin and crank journal:
Out-of-roundness
0.030 mm (0.0012 in) or less
Taper limit
0.07 mm (0.0028 in)
Grinding limit
0.25 mm (0.0098 in)
Unit: mm (in)
Crank journal diameter
Crank pin diameter
#1, #5 #2, #3, #4
StandardJournal O.D.59.992—60.008
(2.3619—2.3625)59.992—60.008
(2.3619—2.3625)51.984—52.000
(2.0466—2.0472)
Bearing size
(Thickness at
center)1.998—2.011
(0.0787—0.0792)2.000—2.013
(0.0787—0.0793)1.492—1.501
(0.0587—0.0591)
0.03 (0.0012)
undersizeJournal O.D.59.962—59.978
(2.3607—2.3613)59.954—59.970
(2.3604—2.3610)51.954—51.970
(2.0454—2.0461)
Bearing size
(Thickness at
center)2.017—2.020
(0.0794—0.0795)2.019—2.022
(0.0795—0.0796)1.510—1.513
(0.0594—0.0596)
0.05 (0.0020)
undersizeJournal O.D.59.934—59.950
(2.3596—2.3602)59.934—59.950
(2.3596—2.3602)51.934—51.950
(2.0446—2.0453)
Bearing size
(Thickness at
center)2.027—2.030
(0.0798—0.0799)2.029—2.032
(0.0799—0.0800)1.520—1.523
(0.0598—0.0600)
0.25 (0.0098)
undersizeJournal O.D.59.742—59.758
(2.3520—2.3527)59.734—59.750
(2.3517—2.3524)51.734—51.750
(2.0368—2.0374)
Bearing size
(Thickness at
center)2.127—2.130
(0.0837—0.0839)2.129—2.132
(0.0838—0.0839)1.620—1.623
(0.0638—0.0639)
O.D. ... Outer Diameter
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G2M0180
4) Measure the thrust clearance of crankshaft at center
bearing. If the clearance exceeds the limit, replace bearing.
Crankshaft thrust clearance:
Standard
0.030—0.115 mm (0.0012—0.0045 in)
Limit
0.25 mm (0.0098 in)
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 measurement is not within
the specification, replace defective bearing with an under-
size one, and replace or recondition crankshaft as neces-
sary.
Unit: mm (in)
Crankshaft oil clearance
Standard#1, #50.003—0.030
(0.0001—0.0012)
#2, #3, #40.010—0.033
(0.0004—0.0013)
Limit#1, #3, #5 0.040 (0.0016)
#2, #4 0.035 (0.0014)
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2-3SERVICE PROCEDURE
7. Cylinder Block

D: ASSEMBLY
1. CRANKSHAFT AND PISTON
B2M0127A
Tightening torque: N⋅m (kg-m, ft-lb)
T: 44±2 (4.5±0.2, 32.5±1.4)
1) Install connecting rod bearings on connecting rods and
connecting rod caps.
CAUTION:
Apply oil to the surfaces of the connecting rod bear-
ings.
2) Install connecting rod on crankshaft.
CAUTION:
Position each connecting rod with the side marked
facing forward.
3) Install connecting rod cap with connecting rod nut.
Ensure the arrow on connecting rod cap faces the front
during installation.
CAUTION:
Each connecting rod has its own mating cap. Make
sure that they are assembled correctly by checking
their matching number.
When tightening the connecting rod nuts, apply oil
on the threads.
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B2M1211A
4) Installation of piston rings and oil ring
(1) Install oil ring spacer, upper rail and lower rail in this
order by hand. Then install second ring and top ring
with a piston ring expander.
(2) Position the top ring gap at A or B in the Figure.
(3) Position the second ring gap at 180°on the reverse
side for the top ring gap.
B2M1212A
(4) Position the upper rail gap at C or D in the Figure.
(5) Position the expander gap at 180°of the reverse
side for the upper rail gap.
(6) Position the lower rail gap at E or F in the Figure.
CAUTION:
Ensure ring gaps do not face the same direction.
Ensure ring gaps are not within the piston skirt area.
G2M0183
5) Install circlip.
Install circlips in piston holes located opposite service
holes in cylinder block, when positioning all pistons in the
corresponding cylinders.
CAUTION:
Use new circlips.
NOTE:
Piston front mark“
”facer toward front of engine.
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7. Cylinder Block

B2M0087A
2. CYLINDER BLOCK
1) Install ST to cylinder block, then install crankshaft bear-
ings.
ST 499817000 ENGINE STAND
CAUTION:
Remove oil the mating surface of bearing and cylinder
block before installation. Also apply a coat of engine
oil to crankshaft pins.
2) Position crankshaft on the #2 and #4 cylinder block.
Tightening torque:
T1: 25±2 N⋅m (2.5±0.2 kg-m, 18.1±1.4 ft-lb)
T2: 47±3 N⋅m (4.8±0.3 kg-m, 34.7±2.2 ft-lb)
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7. Cylinder Block