Subaru Legacy 2005 Service Manual page 1151

4) Check the snap ring installation groove on the
piston for burr (A). If necessary, remove burr from
the groove so that the piston pin can lightly move.
(A)
5) Check the piston pin snap ring for distortion,
cracks and wear.
4. PISTON RING
1) If the piston ring is broken, damaged or worn, or
if its tension is insufficient, or when the piston is re-
placed, replace the piston ring with a new one of
the same size as the piston.
CAUTION:
• Marks are displayed on the end of top and
second rings. When installing the rings to the
piston, face those marks upward.
• Oil ring consists of the upper rail, expander
and lower rail. When installing on piston, be
careful of each rail's direction.
(A) Upper rail
(B) Expander
(C) Lower rail
Cylinder Block
2) Squarely place the piston ring and oil ring in cyl-
inder, and measure the piston ring gap with a thick-
ness gauge.
Piston
ring gap
ME-00175
NOTE:
The difference between the outer and inner circle
side of top ring must be less than 0.05 mm (0.0020
in).
3) Measure the clearance between piston ring and
piston ring groove using thickness gauge.
NOTE:
Before measuring the clearance, clean the piston
(A)
ring groove and piston ring.
(B)
(C)
Clearance
between pis-
ton ring and
piston ring
(A)
groove
(B)
(C)
ME-02480
ME(H4DOTC)-85
Standard
mm (in)
Outer circle side: 0.20 — 0.25
(0.0079 — 0.0098)
Top ring
Inner circle side: 0.20 — 0.30
(0.0079 — 0.012)
Second 0.40 — 0.50
ring (0.016 — 0.020)
Oil ring 0.20 — 0.50
rail (0.0079 — 0.0197)
Standard
0.040 — 0.080
Top ring
(0.0016 — 0.0031)
Second 0.030 — 0.070
ring (0.0012 — 0.0028)
MECHANICAL
ME-00177
mm (in)
ME-00178