Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 74

ME(STI)-58

Timing Belt

MECHANICAL

C: INSPECTION

1. TIMING BELT

1) Check the timing belt teeth for breaks, cracks or

wear. If any fault is found, replace the timing belt.

2) Check the condition on the back surface of the

timing belt. If cracks are found, replace the timing

belt.
CAUTION:

• Be careful not to let oil, grease or coolant

contact the timing belt. Remove quickly and

thoroughly if this happens.

• Do not bend the timing belt sharply.
In radial diameter h:

60 mm (2.36 in) or more

2. AUTOMATIC BELT TENSION ADJUST-

ER

1) Visually check the oil seals for leaks, and rod

ends for abnormal wear and scratches. If neces-

sary, replace the automatic belt tension adjuster

assembly.
NOTE:

Slight traces of oil at the rod oil seal does not indi-

cate a problem.

2) Check that the adjuster rod does not move when

a pressure of 165 N (16.8 kgf, 37.1 lbf) is applied to

it. This is to check adjuster rod stiffness.

3) If the adjuster rod is not stiff enough and moves

freely when applying 165 N (16.8 kgf, 37.1 lbf),

check it using the following procedures:

(1) Slowly press the adjuster rod down to the

end surface of cylinder. Repeat this operation

two to three times.

(2) With the adjuster rod moved all the way up,

apply a pressure of 165 N (16.8 kgf, 37.1 lbf) to

it, and check the adjuster rod stiffness.

(3) If the adjuster rod is not stiff and moves

down, replace the automatic belt tension adjust-

er assembly with a new part.

CAUTION:

• Always use a vertical type pressing tool to

move the adjuster rod down.

• Do not use a lateral type vise.

• Push the adjuster rod vertically.

• Press-in the push adjuster rod gradually tak-

ing three minutes or more.

• Do not allow press pressure to exceed 9,807

N (1,000 kgf, 2,205 lbf).

• Push in the adjuster rod to the end face of the

cylinder. However, do not press the adjuster

rod below the end face of the cylinder. Doing so

may damage the cylinder.

4) Measure the amount of adjuster rod protrusion

“L” from the end surface of the cylinder. If it is not

within specifications, replace the automatic belt

tension adjuster assembly with a new part.
Protrusion amount of adjuster rod L:

5.2 — 6.2 mm (0.205 — 0.244 in)

3. BELT TENSION PULLEY

1) Check the mating surfaces of timing belt and

contact point of adjuster rod for abnormal wear or

scratches. Replace the automatic belt tension ad-

juster assembly with a new part if faulty.

2) Check the belt tension pulley for smooth rota-

tion. Replace the automatic belt tension adjuster

assembly with a new part if abnormal noise or ex-

cessive play occurs.

3) Check the belt tension pulley for grease leakage.

4. BELT IDLER

1) Check the belt idler for smooth rotation. Replace

if noise or excessive play occurs.

2) Check the outer contacting surfaces of idler pul-

ley for abnormal wear and scratches.

3) Check the belt idler for grease leakage.

ME-00248

h

ME-04106

L

ME(STI)-59

Cam Sprocket

MECHANICAL

16.Cam Sprocket

A: REMOVAL

NOTE:

When replacing a single part, perform the work with

the engine assembly installed to body.

1) Remove the crank pulley. <Ref. to ME(STI)-47,

REMOVAL, Crank Pulley.>

2) Remove the timing belt cover. <Ref. to ME(STI)-

49, REMOVAL, Timing Belt Cover.>

3) Remove the timing belt. <Ref. to ME(STI)-50,

REMOVAL, Timing Belt.>

4) Remove the actuator covers of the intake and

exhaust cam sprockets.

5) Use the ST to lock the cam sprocket, and re-

move the cam sprocket bolt.

ST 499977500

CAM SPROCKET WRENCH

6) Remove the cam sprocket.

B: INSTALLATION

1) Install the cam sprocket.

2) Use the ST to lock the cam sprocket, and install

the cam sprocket bolt.
NOTE:

Do not confuse cam sprockets (LH) and (RH), and

(INT) and (EXH) during installation.

ST 499977500

CAM SPROCKET WRENCH

Tightening torque:

Tighten to 30 N·m (3.1 kgf-m, 22.1 ft-lb) of

torque, and then tighten further by 45°.

3) Attach the actuator covers of the intake and ex-

haust cam sprockets.
NOTE:

Use new O-rings.
Tightening torque:

3.4 N·m (0.3 kgf-m, 2.5 ft-lb)

4) Install the timing belt. <Ref. to ME(STI)-52, IN-

STALLATION, Timing Belt.>

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

49, INSTALLATION, Timing Belt Cover.>

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

STALLATION, Crank Pulley.>

C: INSPECTION

1) Check the cam sprocket teeth for abnormal wear

and scratches.

2) Make sure there is no free play between cam

sprocket and key.

ME-03332

ST

ME-03332

ST

ME(STI)-60

Crank Sprocket

MECHANICAL

17.Crank Sprocket

A: REMOVAL

NOTE:

When replacing a single part, perform the work with

the engine assembly installed to body.

1) Remove the crank pulley. <Ref. to ME(STI)-47,

REMOVAL, Crank Pulley.>

2) Remove the timing belt cover. <Ref. to ME(STI)-

49, REMOVAL, Timing Belt Cover.>

3) Remove the timing belt. <Ref. to ME(STI)-50,

REMOVAL, Timing Belt.>

4) Remove the crank sprocket.

B: INSTALLATION

1) Install the crank sprocket.

2) Install the timing belt. <Ref. to ME(STI)-52, IN-

STALLATION, Timing Belt.>

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

49, INSTALLATION, Timing Belt Cover.>

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

STALLATION, Crank Pulley.>

C: INSPECTION

1) Check the crank sprocket teeth for abnormal

wear and scratches.

2) Make sure there is no free play between crank

sprocket and key.

3) Check the crank sprocket protrusion used for

sensor for damage and contamination of foreign

matter.

ME-04983

ME-04983

ME(STI)-61

Camshaft

MECHANICAL

18.Camshaft

A: REMOVAL

1) Remove the engine from the vehicle. <Ref. to

ME(STI)-30, REMOVAL, Engine Assembly.>

2) Remove the rear side belt. <Ref. to ME(STI)-40,

REAR SIDE BELT, REMOVAL, V-belt.>

3) Remove the crank pulley. <Ref. to ME(STI)-47,

REMOVAL, Crank Pulley.>

4) Remove the timing belt cover. <Ref. to ME(STI)-

49, REMOVAL, Timing Belt Cover.>

5) Remove the timing belt. <Ref. to ME(STI)-50,

REMOVAL, Timing Belt.>

6) Remove the cam sprocket. <Ref. to ME(STI)-59,

REMOVAL, Cam Sprocket.>

7) Disconnect the connector from the intake oil flow

control solenoid valve.

8) Disconnect the connector (A) from the exhaust

camshaft position sensor and the connector (B)

form the exhaust oil flow control solenoid valve.

9) Remove the timing belt cover No. 2 RH (A) and

timing belt cover No. 2 LH (B).
NOTE:

When removing the timing belt cover, be careful not

to damage the seal rubber.

10) Remove the tensioner bracket.

ME-05990

ME-05025

(B)

(B)

(A)

(A)

ME-04836

(B)

(A)

ME-04984