Front Suspension System (Except Sti): Other Subaru Impreza GH

CAUTION

1. Wear appropriate work clothing, including a cap, protective goggles and protective shoes when performing any work.
2. Before removal, installation or disassembly, be sure to clarify the failure. Avoid unnecessary removal, installation, disassembly and replacement.
3. Use SUBARU genuine grease etc. or equivalent. Do not mix grease etc. of different grades or manufacturers.
4. Before securing a part on a vise, place cushioning material such as wood blocks, aluminum plate, or cloth between the part and the vise.
5. Be sure to tighten fasteners including bolts and nuts to the specified torque.
6. Place shop jacks or rigid racks at the specified points.

GENERAL TOOL

GENERAL TOOL CHART

CAMBER

1. Inspection

Scheme 70

1. Place the front wheel on the turning radius gauge. Make sure the ground contact surfaces of the front and rear wheels are at the same height.
2. Set the adapter into the center of wheel, and then set the wheel alignment gauge.
3. Measure the camber angle in accordance with the operation information for wheel alignment gauge.

CAMBER ANGLE CHART

1. Front camber adjustment

Scheme 71

1. When adjusting the camber, adjust it to the following value. CAMBER ANGLE CHART Model Camber (Difference between RH and LH 45' or less) Except for OUTBACK -0°10'±0°30' OUTBACK -0°05'±0°30'
2. Loosen the two flange nuts located at the front lower part of the strut. NOTE: When the adjusting bolt needs to be loosened or tightened, hold its head with a wrench and turn the flange nut.
3. Turn the camber adjusting bolt so that the camber is set at specification. NOTE: Moving the adjusting bolt by one scale changes the camber by approximately 0°15'. CAMBER ANGLE CHART To increase camber. Rotate the left side counterclockwise. Rotate the right side clockwise. CAMBER ANGLE CHART To decrease camber. Rotate the left side clockwise. Rotate the right side counterclockwise.
4. Tighten two new flange nuts. Tightening torque: 155 N.m (15.8 kgf-m, 114.3 ft-lb)

CASTER

1. Inspection

Scheme 72

1. Place the front wheel on the turning radius gauge. Make sure the ground contact surfaces of the front and rear wheels are at the same height.
2. Set the adapter into the center of wheel, and then set the wheel alignment gauge.
3. Measure the caster angle in accordance with the operation instructions for wheel alignment gauge. CASTER ANGLE CHART Model Caster Except for OUTBACK 5°55' OUTBACK 5°50'

STEERING ANGLE

1. Inspection

1. Place the vehicle on turning radius gauge.
2. While depressing the brake pedal, turn the steering wheel fully to the left and right. With the steering wheel held at each fully turned position, measure both the inner and outer wheel steering angles. STEERING ANGLE CHART Model Inner wheel Outer wheel OUTBACK 37.9°±1.5° 33.5°±1.5° WRX-SS 37.2°±1.5° 32.9°±1.5° Other than above 37.8°±1.5° 33.4°±1.5°

1. Adjustment

1. Turn the tie-rod to adjust the steering angle of both inner and outer wheels.
2. Check the toe-in.

Note. Correct the boot if it is twisted.

Scheme 73

FRONT WHEEL TOE-IN

1. Inspection

Toe-in: 0±3 mm (0±0.12 in)

Scheme 74

1. Set the toe-in gauge in the position at wheel axis center height behind the right and left front tires.
2. Place a mark at the center of both left and right tires, and measure distance "A" between the marks.
3. Move the vehicle forward to rotate the tires 180°. NOTE: Be sure to rotate the tires in the forward direction.
4. Measure the distance "B" between the left and right marks. Find toe-in using the following calculation: A - B = Toe-in

1. Adjustment

When adjusting the toe-in, adjust it to the following value.

Toe-in: 0±2 mm (0±0.08 in)

Scheme 75

1. Check that the left and right wheel steering angles are within specification.
2. Loosen the left and right side steering tie-rod lock nuts.
3. Turn the left and right tie-rods by equal amounts until the toe-in is at the specification. Both the left and right tie-rods are right-hand threaded. To increase toe-in, turn both tie-rods clockwise by equal amount (viewing from the inside of vehicle).
4. Tighten the tie-rod lock nut. Tightening torque: 85 N.m (8.7 kgf-m, 62.7 ft-lb) NOTE: Check and correct the tie-rod boot if twisted.

REAR WHEEL TOE-IN

1. Inspection

Toe-in: 0±3 mm (0±0.12 in)

Refer to FRONT WHEEL TOE-IN for rear toe-in inspection procedures.

. Refer to FRONT WHEEL TOE-IN , INSPECTION, Wheel Alignment.

1. ADJUSTMENT

When adjusting, adjust it to the following value.

Toe-in: 0±2 mm (0±0.08 in)

Scheme 76

1. Loosen the self-locking nut on the inner side of front lateral ink. NOTE: When loosening or tightening the adjusting bolt, hold the bolt head and turn the self-locking nut.
2. Turn the adjusting bolt until toe-in is within the specification. NOTE: When the left and right wheels are adjusted for toe-in at the same time, the movement of one scale graduation changes toe-in by approx. 1.3 mm (0.05 in). TOE-IN CHART To increase toe-in. Rotate the left side clockwise. Rotate the right side counterclockwise. TOE-IN CHART To decrease toe-in. Rotate the left side counterclockwise. Rotate the right side clockwise.
3. Attach and tighten a new self-locking nut. Tightening torque: 100 N.m (10.2 kgf-m, 73.8 ft-lb)

THRUST ANGLE

1. 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

Scheme 77

1. 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 direction, adjust the other rear wheel equally in toe-out direction, in order to make the thrust angle adjustment.
3. When the left and right adjusting bolts are turned by one graduation, the thrust angle will change approx. 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 direction while slanting in the oblique direction depending on the degree of the mean thrust angle.

Scheme 78

Thrust angle: gamma=(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 a and p in the calculation.

Scheme 79

FRONT BUSHING

Using the ST and a press, remove the front bushing.

ST 927680000 INSTALLER & REMOVER SET

Scheme 80

Scheme 81

1. Put an alignment mark on the front arm based on the center of rear bushing recess portion. CAUTION: Always put an alignment mark for aligning the position on bushing installation.
2. Using the ST and a press, remove the rear bushing.

ST1 20299AG000 REMOVER

ST2 20299AG010 BASE

Scheme 82

Assemble in the reverse order of disassembly.

Scheme 83

Scheme 84

Scheme 85

1. Install the rear bushing with its longer inner cylinder facing upward and the shorter facing downward and protruding part rearward as shown in the figure.
2. Align the center of rear bushing recess portion with the aligning mark on the front arm.
3. Using the ST and a press, install the rear bushing. ST1 20299AG000 REMOVER ST2 20299AG010 BASE

STRUT

1. Check for oil leaks.
2. Move the piston rod up and down to check that it operates smoothly without any hitch.
3. Piston rod play

1. Measure the play as follows

Fix the outer shell in place and fully extend the rod. Set a dial gauge at the end of rod L [10 mm (0.39 in)], and then read the dial gauge indication P 1 while applying a force of W [20 N (2 kgf, 4 lbf)] to the threaded portion. Apply a force of 20 N (2 kgf, 4 lbf) from the opposite direction of "W", and then read the dial gauge indication P 2 .

Scheme 86

Play limit (P 1 + P 2 )

0.8 mm (0.031 in)

If the play exceeds limit, replace the strut.

STRUT MOUNT

Check the rubber part for deformation, cracks or deterioration, and then replace it with a new part if defective.

DUST COVER

If major cracks or damage are found, replace it with a new part.

COIL SPRING

If a permanent strain is found, replaced it with a new part.

HELPER

If major cracks or damage are found, replace it with a new part.

DISPOSAL

Scheme 87

1. Place the strut on a level surface with the piston rod fully expanded.
2. Using a 2 - 3 mm (0.08 - 0.12 in) dia. drill, make holes in areas shown in the figure.

Scheme 88

1. Lift up the vehicle, and then remove the front wheels.
2. Remove the front exhaust pipe.
3. Remove the front crossmember support plate. Refer to «REMOVAL»(ref-357247-S14330456142010031100000) , Front Crossmember Support Plate.
4. Remove the front stabilizer. Refer to «REMOVAL»(ref-357247-S14436317242010031100000) , Front Stabilize.
5. Disconnect the tie-rod end from housing.
6. Remove the front arm. Refer to «REMOVAL»(ref-357247-S38160440092010031100000) , Front Arm.
7. Remove the nuts attaching the engine mount cushion rubber to crossmember.
8. Remove the steering universal joint.
9. Disconnect the power steering hose from steering gearbox.
10. Lift the engine approx. 10 mm (0.39 in) using a chain block.
11. Support the crossmember with a jack, remove the bolts securing crossmember to body, and then gradually lower the crossmember with steering gearbox as a unit.

Scheme 89

IMPROPER VEHICLE POSTURE OR IMPROPER WHEEL ARCH HEIGHT

POSSIBLE CAUSE CHART

POOR RIDE COMFORT

1. Large rebound shock
2. Rocking of the vehicle continues too long after running over bump and hump.
3. Excessive shock in bumping

POSSIBLE CAUSE CHART