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Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual - part 71

ME(STI)-46

V-belt

MECHANICAL

C: INSPECTION

1. FRONT SIDE BELT

CAUTION:

Check and adjust the front side belt tension so

that it is within the specified range. Using the

belt with a tension out of the specified range

may result in a fault such as the following:

• If the front side belt tension is higher, unex-

pected force is generated at the power steering

oil pump, generator and crankshaft bearing,

causing abnormal noise due to abnormal wear

of the bearing.

• If the front side belt tension is lower, the front

side belt and crank pulley slip, causing abnor-

mally high temperature on the crank pulley due

to frictional heat. If this condition repeatedly

occurs, the front side belt may abnormally

wear, causing abnormal noise, front side belt

damage or crank pulley damage.

1) Replace the front side belt, if crack, fraying or

wear is found.

2) Check the front side belt tension and adjust it if

necessary by changing the generator installing po-

sition.
Front side belt tension (with belt tension

gauge):

When installing new parts

640 — 780 N (65 — 80 kgf, 144 — 175 lbf)

At inspection

490 — 640 N (50 — 65 kgf, 110 — 144 lbf)

Front side belt tension (without belt tension

gauge):

When installing new parts

7 — 9 mm (0.276 — 0.354 in)

At inspection

9 — 11 mm (0.354 — 0.433 in)

2. REAR SIDE BELT

Replace the rear side belt, if crack, fraying or wear

is found, or noise is emitted.
NOTE:

For the rear side belt, a stretch type belt is used,

and therefore, it is not necessary to check deflec-

tion nor tension.

(A) Front side belt
(B) Rear side belt

C/P Crank pulley

GEN Generator pulley

P/S Power steering oil pump pulley

A/C A/C compressor pulley

ME-03313

C/P

P/S

A/C

GEN

(A)

(B)

(A) Front side belt
(B) Rear side belt

C/P Crank pulley

GEN Generator pulley

P/S Power steering oil pump pulley

A/C A/C compressor pulley

ME-03314

(A)

(B)

GEN

C/P

A/C

P/S

(C)

ME(STI)-47

Crank Pulley

MECHANICAL

13.Crank Pulley

A: REMOVAL

NOTE:

When replacing a single part, perform the work with

the engine assembly installed to body.

1) Remove the V-belts. <Ref. to ME(STI)-40, RE-

MOVAL, V-belt.>

2) Use the ST to lock the crank pulley, and remove

the crank pulley bolt.

ST 499977100

CRANK PULLEY WRENCH

3) Remove the crank pulley.

B: INSTALLATION

1. METHOD WITHOUT ANGLE GAUGE

1) Clean the crankshaft thread using compressed

air.

2) Install the crank pulley.

3) Apply engine oil to the crank pulley bolt seat and

thread.

4) Tighten the crank pulley bolts.

(1) Use the ST to lock the crank pulley, and

temporarily tighten the crank pulley bolt.

ST 499977100

CRANK PULLEY WRENCH

Tightening torque:

47 N·m (4.8 kgf-m, 34.7 ft-lb)

(2) Draw reference lines (A) and (B) using a

marker to set the socket to the crank pulley bolt

as shown in the figure.

NOTE:

Set the socket onto the crank pulley bolt so that ref-

erence lines (A) and (B) is visible.

ST 499977100

CRANK PULLEY WRENCH

(3) Draw end line (C) on ST using a marker at

the same position as reference line (B) drawn

on the socket in step (2).

ST 499977100

CRANK PULLEY WRENCH

ME-04141

ME-04142

(a) When using 6-point socket
(b) When using 12-point socket

ME-04955

(B)

(A)

(a)

(B)

(A)

(b)

(B)

(A)

ME-04144

(B)

(C)

ME(STI)-48

Crank Pulley

MECHANICAL

(4) Use the ST to lock the crank pulley, and

tighten the crank pulley bolt to the angle where

reference line (A) and end line (C) are aligned.

NOTE:

It should be approx. 60° when reference line (A)

and end line (C) are aligned.

ST 499977100

CRANK PULLEY WRENCH

Tightening angle:

60°

5°

5) Install the V-belts. <Ref. to ME(STI)-40, IN-

STALLATION, V-belt.>

2. METHOD WITH ANGLE GAUGE

1) Clean the crankshaft thread using compressed

air.

2) Install the crank pulley.

3) Apply engine oil to the crank pulley bolt seat and

thread.

4) Tighten the crank pulley bolts.

(1) Remove the radiator main fan motor assem-

bly and radiator sub fan motor assembly. <Ref.

to CO(STI)-23, REMOVAL, Radiator Main Fan

and Fan Motor.> <Ref. to CO(STI)-25, REMOV-

AL, Radiator Sub Fan and Fan Motor.>

(2) Use the ST to lock the crank pulley, and

temporarily tighten the crank pulley bolt.

ST 499977100

CRANK PULLEY WRENCH

Tightening torque:

47 N·m (4.8 kgf-m, 34.7 ft-lb)

(3) Set the angle gauge, use the ST to lock the

crank pulley, and tighten the crank pulley bolt to

the specified angle.

ST 499977100

CRANK PULLEY WRENCH

Tightening angle:

60°

5°

(4) Install the radiator main fan motor assembly

and radiator sub fan motor assembly. <Ref. to

CO(STI)-23, INSTALLATION, Radiator Main

Fan and Fan Motor.> <Ref. to CO(STI)-25, IN-

STALLATION, Radiator Sub Fan and Fan Mo-

tor.>

5) Install the V-belts. <Ref. to ME(STI)-40, IN-

STALLATION, V-belt.>

C: INSPECTION

1) Check that the crank pulley has no deformation,

cracks or other damages.

ME-04145

(A)

(C)

ME-07558

ME-07555

ME(STI)-49

Timing Belt Cover

MECHANICAL

14.Timing Belt Cover

A: REMOVAL

NOTE:

When replacing a single part, perform the work with

the engine assembly installed to body.

1) Remove the secondary air pump. <Ref. to

EC(STI)-27, REMOVAL, Secondary Air Pump.>

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

REMOVAL, Crank Pulley.>

3) Remove the timing belt cover RH (B) together

with the engine harness cover (A).

4) Remove the timing belt cover LH (C).

5) Remove the front timing belt cover (D).

B: INSTALLATION

1) Install the front timing belt cover (D).
Tightening torque:

5 N·m (0.5 kgf-m, 3.7 ft-lb)

2) Install the timing belt cover LH (C).
Tightening torque:

5 N·m (0.5 kgf-m, 3.7 ft-lb)

3) Install the timing belt cover RH (B) together with

the engine harness cover (A).
Tightening torque:

5 N·m (0.5 kgf-m, 3.7 ft-lb)

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

STALLATION, Crank Pulley.>

5) Install the secondary air pump. <Ref. to

EC(STI)-27, INSTALLATION, Secondary Air

Pump.>

C: INSPECTION

Check the timing belt cover for damage.

ME-04762

(B)

(D)

(C)

(A)

ME-04762

(B)

(D)

(C)

(A)

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