Subaru Impreza 2003 Service Manual page 1080

MECHANICAL
5. CONNECTING ROD
1) Replace the connecting rod, if the large or small
end thrust surface is damaged.
2) Check for bend or twist using a connecting rod
aligner. Replace the 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)
( B )
(A) Thickness gauge
(B) Connecting rod
3) Install the connecting rod fitted with bearing to
crankshaft, and then measure the side clearance
(thrust clearance). Replace the 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
0.40 mm (0.016 in)
CYLINDER BLOCK
( A )
( B )
( A )
ME-00179
ME-00180
ME(H4DOTC)-106
4) Inspect the connecting rod bearing for scar,
peeling, seizure, melting, wear, etc.
5) Measure the oil clearance on individual connect-
ing 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
0.020 — 0.046 mm (0.0008 — 0.0018 in)
Limit
0.050 mm (0.0020 in)
Bearing size
Bearing (Thickness at cen-
ter)
1.486 — 1.498
Standard
(0.0585 — 0.0590)
0.03
1.504 — 1.512
(0.0012)
(0.0592 — 0.0595)
undersize
0.05
1.514 — 1.522
(0.0020)
(0.0596 — 0.0599)
undersize
0.25
1.614 — 1.622
(0.0098)
(0.0635 — 0.0639)
undersize
6) Inspect the bushing at connecting rod small end,
and replace if worn or damaged. Also measure the
piston pin clearance at connecting rod small end.
Unit: mm (in)
Outer diameter of
crank pin
51.984 — 52.000
(2.0466 — 2.0472)
51.954 — 51.970
(2.0454 — 2.0461)
51.934 — 51.950
(2.0447 — 2.0453)
51.734 — 51.750
(2.0368 — 2.0374)