Subaru 2003 LEGACY Service Manual page 35

MECHANICAL
4) Check the circlip installation groove on piston for
burr (A). If necessary, remove the burr from groove
so that the piston pin can lightly move.
( A )
5) Check the piston pin circlip 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.
NOTE:
• Marks are shown on the end of top and second
rings. When installing the rings to piston, face this
mark upward.
• Oil ring consists of upper rail, expander and low-
er rail. When installing on piston, be careful of each
rail's direction.
(A) Upper rail
(B) Expander
(C) Lower rail
CYLINDER BLOCK
ME-00175
(A)
(B)
(C)
(A)
(B)
(C)
ME-00375
ME(H4DOSTC)-86
2) Clean up the piston ring groove and piston ring.
3) Squarely place the piston ring and oil ring in cyl-
inder, and then measure the piston ring gap with a
thickness gauge.
Top ring
(0.0079 — 0.0098)
Piston Second
ring gap ring (0.0138 — 0.0197)
Oil ring
rail (0.0079 — 0.0197)
4) Measure the clearance between piston ring and
piston ring groove with a thickness gauge.
NOTE:
Before measuring the clearance, clean the piston
ring groove and piston ring.
Clearance
Top ring
between pis-
ton ring and
piston ring
Second
groove
ring
Unit: mm (in)
Standard Limit
0.20 — 0.25
1.0 (0.039)
0.35 — 0.50
1.0 (0.039)
0.20 — 0.50
1.5 (0.059)
ME-00177
Unit: mm (in)
Standard Limit
0.055 — 0.090
(0.0022 — 0.15 (0.0059)
0.0035)
0.030 — 0.070
(0.0012 — 0.15 (0.0059)
0.0028)
ME-00178