Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 81

ME(STI)-86

Cylinder Block

MECHANICAL

11) Tighten the 8 mm and 6 mm cylinder block con-

necting bolts on the LH side (A — H) in alphabetical

order.
Tightening torque:

(A) — (G): 25 N·m (2.5 kgf-m, 18.4 ft-lb)

(H): 6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

12) Apply a coat of engine oil to the oil seal inner

periphery and outer periphery, and install the rear

oil seal using ST1 and ST2.
NOTE:

Use a new rear oil seal.

ST1 499597100

CRANKSHAFT OIL SEAL

GUIDE

ST2 499587200

CRANKSHAFT OIL SEAL IN-

STALLER

13) Position the top ring gap at (A) or (B) in the fig-

ure.

14) Position the second ring gap at 180° on the re-

verse side the top ring gap.

15) Position the upper rail gap at (C) in the figure.

16) Align the upper rail spin stopper (E) to the side

hole (D) on the piston.

17) Position the expander gap at (F) in the figure on

the 180° opposite direction of (C).

18) Set the lower rail gap at position (G), located

120° clockwise from (C) in the figure.

NOTE:

• Make sure ring gaps do not face the same direc-

tion.

• Make sure ring gaps are not within the piston

skirt area.

(A) Rear oil seal
(B) Flywheel attachment bolt

ME-00147

(B)

(C)

(D)

(E)

(F)

(G)

(H)

(A)

ME-04998

ST1

ST2

(B)

(A)

ME-04737

(A)

(B)

ME-04738

(C)

25

ME-02471

(E)

(D)

ME-04739

(F)

ME-04740

120

(C)

(G)

ME(STI)-87

Cylinder Block

MECHANICAL

19) Install the snap ring.

Before positioning the piston on the cylinder block, attach the snap ring in the service hole of the cylinder

block, and the piston hole on the opposite side.
NOTE:

Use new snap rings.

(A) Front side

ME-04764

#4

#3

#2

#1

(A)

(1)

Piston

(4)

Gasket

Tightening torque: N·m (kgf-m, ft-lb)

(2)

Piston pin

(5)

Service hole plug

T: 70 (7.1, 51.6)

(3)

Snap ring

ME-04730

(1)

(1)

(2)

(2)

(3)

(3)

(4)

(4)

(5)

(5)

T

ME(STI)-88

Cylinder Block

MECHANICAL

20) Install the piston.

(1) Set the parts so that the #1 and #2 cylinders

are on the upper side.

(2) Using the ST1, turn the crankshaft so that

#1 and #2 connecting rods are set at bottom

dead center.

ST1 499987500

CRANKSHAFT SOCKET

(3) Apply a coat of engine oil to the pistons and

cylinders and insert pistons in their cylinders us-

ing ST2.

ST2 498747300

PISTON GUIDE

NOTE:

Face the piston front mark towards the front of the

engine.

21) Install the piston pin.

(1) Apply a coat of engine oil to ST3.

(2) Insert ST3 into the service hole to align the

piston pin hole and the connecting rod small

end.

ST3 499017100

PISTON PIN GUIDE

(3) Apply a thin coat of engine oil to piston pin,

and insert the piston pin into piston and con-

necting rod through service hole.

(4) Install the snap ring.

NOTE:

Use new snap rings.

(5) Apply liquid gasket to the threaded portion

of the service hole plug.

Liquid gasket:

THREE BOND 1105 (Part No. 004403010) or

equivalent

(A) Front mark

ME-00157

ST2

ST1

ME-04830

(A)

ME-00158

ST1

ST3

ME-00159

ME-00160

ME(STI)-89

Cylinder Block

MECHANICAL

(6) Install the service hole plug and gasket.

NOTE:

Use a new gasket.
Tightening torque:

70 N·m (7.1 kgf-m, 51.6 ft-lb)

ME-00140

(1)

Piston

(5)

Service hole plug

Tightening torque: N·m (kgf-m, ft-lb)

(2)

Piston pin

(6)

Service hole cover

T1: 6.4 (0.7, 4.7)

(3)

Snap ring

(7)

O-ring

T2: 70 (7.1, 51.6)

(4)

Gasket

ME-05040

(2)

(3)

(1)

(2)

(6)

(3)

(7)

(4)

(5)

T2

T1

(1)