Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 470

FS-15

Wheel Alignment

FRONT SUSPENSION

7. THRUST ANGLE

• Inspection
1) Park the vehicle on a level surface.

2) Move the vehicle 3 to 4 meters (10 to 13 feet)

straight forward.

3) Draw the center of loci for both the front and rear

axles.

4) Measure distance “L” between the center lines of

the axle loci.
Thrust angle

0°

±

30

′

Less than 30

′

when “L” is 23 mm (0.9 in) or

less

• Adjustment
When adjusting, adjust it to the following value.
Thrust angle

0°

±

20

′

Less than 20

′

when “L” is 15 mm (0.6 in) or

less

1) Make thrust angle adjustments by turning the

toe-in adjusting bolts of the rear suspension equally

in the same direction.

2) When one rear wheel is adjusted in a toe-in di-

rection, adjust the other rear wheel equally in toe-

out direction, in order to make the thrust angle ad-

justment.

3) When the left and right adjusting bolts are turned

by one graduation, the thrust angle will change ap-

prox. 15′ (“L” is approx. 11 mm (0.43 in)).
NOTE:

Thrust angle is a mean value of left and right wheel

toe angles in relation to the vehicle body center

line. Vehicle is driven straight in the thrust angle di-

rection while slanting in the oblique direction de-

pending on the degree of the mean thrust angle.

Thrust angle:

γ

= (

α

–

β

)/2

α: Rear RH wheel toe-in angle

β: Rear LH wheel toe-in angle

Substitute only the positive toe-in values from each

wheel into α and β in the calculation.

(1) Center line of loci (front axle)
(2) Center line of loci (rear axle)

(1)

(2)

L

FS-00022

(1) Front
(2) Thrust angle
(3) Body center line

(1) Front
(2) Body center line

FS-00024

(2)

(3)

(1)

FS-00976

(1)

(2)

FS-16

Front Crossmember Support Plate

FRONT SUSPENSION

3. Front Crossmember Support

Plate

A: REMOVAL

1) Lift up the vehicle.

2) Remove the front under cover. <Ref. to EI-28,

REMOVAL, Front Under Cover.>

3) Remove the bolt, and remove the front cross-

member support plate.

B: INSTALLATION

Install each part in the reverse order of removal.
Tightening torque:

60 N·m (6.1 kgf-m, 44.3 ft-lb)

FS-00104

FS-17

Front Stabilizer

FRONT SUSPENSION

4. Front Stabilizer

A: REMOVAL

1) Lift up the vehicle, and then remove the front

wheels.

2) Remove the front under cover. <Ref. to EI-28,

REMOVAL, Front Under Cover.>

3) Remove the front crossmember support plate.

<Ref. to FS-16, REMOVAL, Front Crossmember

Support Plate.>

4) Remove the stabilizer link.

5) Remove the stabilizer bracket.

B: INSTALLATION

Install each part in the reverse order of removal.
CAUTION:

• Use a new flange nut.

• Ensure the stabilizer bushing and stabilizer

have the same identification colors.

• Install the stabilizer bushing (front cross-

member side) while aligning it with the paint

mark on stabilizer.

• The stabilizer bracket has a set orientation.

Install it with the arrow mark facing the upper

side of the vehicle.

Tightening torque:

Stabilizer link:

38 N·m (3.9 kgf-m, 28.0 ft-lb)

Stabilizer bracket:

25 N·m (2.5 kgf-m, 18.4 ft-lb)

Tie-rod end (castle nut):

27 N·m (2.75 kgf-m, 19.9 ft-lb)

C: INSPECTION

1) Check the bushing for abnormal cracks, fatigue

or damage.

2) Check the stabilizer link for damage.

FS-00262

FS-00114

(1) Front side of vehicle

FS-00116

(1)

FS-18

Front Ball Joint

FRONT SUSPENSION

5. Front Ball Joint

A: REMOVAL

1) Lift up the vehicle, and then remove the front

wheels.

2) Remove the front under cover. <Ref. to EI-28,

REMOVAL, Front Under Cover.>

3) Remove the bolt, and remove the front cross-

member support plate.

4) Remove the both sides of stabilizer bracket.

5) Pull out the pin from ball stud, remove the castle

nut, and extract the ball stud from front arm.

6) Remove the bolt installing ball joint to housing.

7) Extract the ball joint from housing.

B: INSTALLATION

1) Insert the ball joint into housing.
CAUTION:

Do not apply grease to the tapered portion of

ball stud.
Tightening torque (Bolt):

50 N·m (5.1 kgf-m, 36.9 ft-lb)

2) Install the ball joint into front arm.
Tightening torque (Castle nut):

39 N·m (4.0 kgf-m, 28.8 ft-lb)

3) Retighten the castle nut further up to 60° until the

hole in the ball stud is aligned with a slot in castle

nut. Then, insert a new cotter pin and bend it

around the castle nut.

4) Install the stabilizer bracket.
NOTE:

The stabilizer bracket has a set orientation. Install it

with the arrow mark facing the upper side of the ve-

hicle.

Tightening torque:

25 N·m (2.5 kgf-m, 18.4 ft-lb)

5) Install the front crossmember support plate.
Tightening torque:

60 N·m (6.1 kgf-m, 44.3 ft-lb)

6) Install the front wheels.

FS-00104

FS-00114

FS-00115

(1) Front side of vehicle

FS-00116

(1)