Subaru 2009 IMPREZA Service Manual page 2226

10.General Diagnostic Table
A: INSPECTION
1. IMPROPER VEHICLE POSTURE OR IMPROPER WHEEL ARCH HEIGHT
(1) Permanent distortion or damaged coil spring
(2) Rough operation of strut or shock absorber
(3) Improper installation of strut or shock absorber
(4) Installation of the wrong coil spring
2. 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
(1) Damaged coil spring
(2) Overinflation of tires
(3) Improper wheel arch height
(4) Fault in operation of strut or shock absorber
(5) Damage or deformation of strut mount or shock absorber mount
(6) Unsuitable length (maximum or minimum) of strut or shock absorber
(7) Deformation or loss of bushing
(8) Deformation or damage of helper in strut assembly or shock absorber
(9) Oil leakage from the strut or shock absorber
3. NOISE
(1) Wear or damage of strut or shock absorber component parts
(2) Loosening of the suspension link installing bolt
(3) Deformation or loss of bushing
(4) Unsuitable length (maximum or minimum) of strut or shock absorber
(5) Damaged coil spring
(6) Wear or damage of the ball joint
(7) Deformation of the stabilizer clamp
General Diagnostic Table
Possible cause
Possible cause
Possible cause
Replace.
Replace.
Replace with proper parts.
Replace with proper parts.
Replace.
Adjust.
Adjust or replace the coil springs with new parts.
Replace.
Replace.
Replace with appropriate parts.
Replace.
Replace.
Replace.
Replace.
Tighten to the specified torque.
Replace.
Replace with appropriate parts.
Replace.
Replace.
Replace.
RS-19
REAR SUSPENSION
Corrective action
Corrective action
Corrective action