Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 73

ME(STI)-54

Timing Belt

MECHANICAL

7) Make sure that the cam and crank sprockets are

positioned properly.
CAUTION:

• Intake and exhaust camshafts for this DOHC

engine can be independently rotated with the

timing belts removed. As can be seen from the

figure, if the intake and exhaust valves are lifted

simultaneously, heads will interfere with each

other, resulting in bent valves.

• When the timing belts are not installed, four

camshafts are held at the “zero-lift” position,

where all cams on camshafts are not pushing

down on the intake and exhaust valves. (Under

this condition, all valves remain unlifted.)

• When the camshafts are rotated to install the

timing belts, #2 intake and #4 exhaust cam of

camshaft LH are held, pushing their corre-

sponding valves down. (Under this condition,

these valves are held lifted.) Camshaft RH are

held so that their cams do not push the valves

down.

• Camshafts LH must be rotated from the zero-

lift position to the position where the timing belt

is to be installed with the smallest possible an-

gle, in order to prevent mutual interference of

intake and exhaust valve heads.

• Do not allow the camshafts to rotate in the di-

rection shown in the upper figure. Doing this

may cause both the intake and exhaust valves

to lift simultaneously, resulting in mutual inter-

ference of valve heads.

(A) Intake camshaft
(B) Exhaust camshaft

ME-04111

(A)

(B)

(A) Direction of rotation
(B) Timing belt installation position

(A)

(A)

(A)

(A)

(B)

(B)

ME-04717

ME(STI)-55

Timing Belt

MECHANICAL

8) Align the alignment mark on the timing belt with marks on the sprockets in the alphabetical order shown

in the figure. While aligning marks, position the timing belt properly, and install the timing belt.
CAUTION:

• If the timing belt slips by 1 or more teeth, the valve and piston may hit each other.

• Make sure that the direction of belt rotation is correct.

9) Install the belt idlers.
Tightening torque:

39 N·m (4.0 kgf-m, 28.8 ft-lb)

NOTE:

Make sure that the marks on the timing belt and

sprockets are aligned.

(1)

Arrow mark

(4)

54.5 teeth

(6)

28 teeth

(2)

Timing belt

(5)

51 teeth

(7)

Install it in the end

(3)

28 teeth

ME-04718

(1)

(2)

(5)

(6)

(4)

(D)

(A)

(C)

(B)

(E)

(3)

RH-IN

RH-EX

LH-EX

LH-IN

(7)

ME-04982

ME(STI)-56

Timing Belt

MECHANICAL

10) After ensuring that the marks on the timing belt

and sprockets are aligned, remove the stopper pin

from tensioner adjuster.

11) Install the timing belt guide.

(1) Temporarily tighten the bolts mounting the

timing belt guide.

NOTE:

• Before installing the timing belt guide, clean the

timing belt guide mounting bolt holes of the timing

belt cover No. 2.

• Apply liquid gasket to the thread of the timing belt

guide mounting bolt on the cam sprocket section.

(when reusing bolts)

Liquid gasket:

THREE BOND 1324 (Part No. 004403042) or

equivalent

ME-00245

ME-00230

ME-03124

ME-03125

ME-03126

ME(STI)-57

Timing Belt

MECHANICAL

(2) Adjust the clearance between timing belt

and timing belt guide using a thickness gauge

and tighten.

Clearance:

1.0

±

0.5 mm (0.039

±

0.020 in)

Tightening torque:

9.75 N·m (1.0 kgf-m, 7.2 ft-lb)

Tightening torque:

6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

12) Install the timing belt cover. <Ref. to ME(STI)-

49, INSTALLATION, Timing Belt Cover.>

13) Install the crank pulley. <Ref. to ME(STI)-47,

INSTALLATION, Crank Pulley.>

ME-00246

ME-03138

ME-03139

ME-03140

ME-00247

ME-03124

ME-03125

ME-03126