Subaru Legacy IV (2008 year). Manual - part 71

ME(H4SO)-80

Cylinder Block

MECHANICAL

C: DISASSEMBLY

1) Remove the connecting rod cap.
2) Remove the connecting rod bearing.

NOTE:
Keep the removed connecting rods, connecting rod
caps and bearings in order so that they are kept in
their original combinations/groups, and not mixed
together.
3) Remove the piston rings using piston ring ex-
pander.
4) Remove the oil ring by hand.

NOTE:
Arrange the removed piston rings in proper order,
to prevent confusion.
5) Remove the snap ring.

(1)

Connecting rod cap

(4)

Second ring

(6)

Snap ring

(2)

Connecting rod bearing

(5)

Oil ring

(7)

Connecting rod

(3)

Top 

ring

  

  

ME-03562

(2)

(2)

(6)

(5)

(4)

(3)

(1)

(7)

ME(H4SO)-81

Cylinder Block

MECHANICAL

D: ASSEMBLY

1) Apply engine oil to the surface of the connecting
rod bearings, and install the connecting rod bear-
ings on connecting rods and connecting rod caps.
2) Position each connecting rod with the side with a
side mark facing forward, and install it.
3) Attach the connecting rod cap, and tighten with
connecting rod nut. Make sure the arrow on con-
necting rod cap faces the front during installation.

NOTE:
• 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.

Tightening torque:

45 N·m (4.6 kgf-m, 33.2 ft-lb)

4) Install the oil ring upper rail, expander and lower
rail by hand.
5) Install the second ring and top ring using piston
ring expander.

NOTE:
Assemble so that the piston ring mark “R” faces the
top side of the piston.

(1)

Connecting rod bearing

(5)

Second ring

Tightening torque:N·m (kgf-m, ft-lb)

(2)

Connecting rod

(6)

Top ring

T: 45 (4.6, 33.2)

(3)

Connecting rod cap

(7)

Snap ring

 

 

(4)

Oil ring

(8)

Side mark

 

 

ME-03154

(2)

(4)

(5)

(6)

(1)

(1)

(7)

(8)

(3)

T

ME(H4SO)-82

Cylinder Block

MECHANICAL

E: INSPECTION

1. CYLINDER BLOCK

1) Check for cracks or damage. Use liquid pene-
trant tester on the important sections to check for
fissures. Check that there are no marks of gas leak-
ing or water leaking on gasket installing surface.
2) Check the oil passages for clogging.
3) Inspect the cylinder block surface that mates
with cylinder head for warping by using a straight
edge, and correct by grinding if necessary.

Warping limit:

0.025 mm (0.00098 in)

Grinding limit:

0.1 mm (0.004 in)

Standard height of cylinder block:

201.0 mm (7.91 in)

2. CYLINDER AND PISTON

1) The cylinder bore size is stamped on the front
upper face of the cylinder block.

NOTE:
• Measurement should be performed at a temper-
ature of 20°C (68°F).
• Standard sized pistons are classified into two
grades, “A” and “B”. These grades should be used
as guide lines in selecting a standard piston.

Standard diameter:

A: 99.505 — 99.515 mm (3.9175 — 3.9179 in)
B: 99.495 — 99.505 mm (3.9171 — 3.9175 in)

(A) Main journal size mark

(B) Cylinder block (RH) — (LH) combination mark

(C) #1 cylinder bore size mark

(D) #2 cylinder bore size mark

(E) #3 cylinder bore size mark

(F) #4 cylinder bore size mark

ME-00170

#5

#4

#3

#2

#1

(A)

(B)

(F)

(D)

A

B

A

B

5

4

5

4

(C)

(E)

ME(H4SO)-83

Cylinder Block

MECHANICAL

2) Measure inner diameter of each cylinder.
Measure the inner diameter of each cylinder in both
the thrust and piston pin directions at the heights as
shown in the figure, using a cylinder bore gauge.

NOTE:
Measurement should be performed at a tempera-
ture of 20°C (68°F).

Taper:

Standard:

0.015 mm (0.0006 in)

Out-of-roundness:

Standard:

0.010 mm (0.0004 in)

3) When the piston is to be replaced due to general
or cylinder wear, select a suitable sized piston by
measuring the piston clearance.

4) Measure outer diameter of each piston.
Measure the outer diameter of each piston at the
height as shown in the figure. (Thrust direction)

NOTE:
Measurement should be performed at a tempera-
ture of 20°C (68°F).

Piston grade point H:

38.2 mm (1.504 in)

Piston outer diameter:

Standard

A: 99.505 — 99.515 mm (3.9175 — 3.9179 in)
B: 99.495 — 99.505 mm (3.9171 — 3.9175 in)

0.25 mm (0.0098 in) oversize:

99.745 — 99.765 mm (3.9270 — 3.9277 in)

0.50 mm (0.0197 in) oversize:

99.995 — 100.015 mm (3.9368 — 3.9376 in)

5) Calculate the clearance between cylinder and
piston.

NOTE:
Measurement should be performed at a tempera-
ture of 20°C (68°F).

Cylinder to piston clearance at 20°C (68°F):

Standard:

–0.010 — 0.010 mm (–0.00039 — 0.00039 in)

(A) Piston pin direction

(B) Thrust direction

H1 10 mm (0.39 in)

H2 45 mm (1.77 in)

H3 80 mm (3.15 in)

H4 115 mm (4.53 in)

ME-00171

(A)

(B)

H2

H1

H3

H4

ME-00172

H