Subaru 2009 IMPREZA Service Manual page 2363

9. General Diagnostic Table
A: INSPECTION
NOTE:
Vibration while cruising may be caused by an unbalanced tire, improper tire inflation pressure, improper
wheel alignment, etc.
Symptoms
Noise or vibration from propeller shaft Center bearing
Abnormal wheel vibration
Noise from the underbody
General Diagnostic Table
Possible cause
Runout of propeller shaft
Loose or gap at connections
Wheel is out of balance.
Front wheel alignment
Rear wheel alignment
Front strut
Rear shock absorber
Front drive shaft
Rear drive shaft
Front hub unit bearing
Rear hub unit bearing
Wheel is out of balance.
Front wheel alignment
Rear wheel alignment
Front strut
Rear shock absorber
DS-35
DRIVE SHAFT SYSTEM
Corrective action
Check the center bearing. <Ref. to DS-12, CEN-
TER BEARING FREE PLAY, INSPECTION, Pro-
peller Shaft.>
Check for deflection of the propeller shaft. <Ref.
to DS-12, RUNOUT OF PROPELLER SHAFT,
INSPECTION, Propeller Shaft.>
Check the joints and connectors. <Ref. to DS-11,
JOINTS AND CONNECTIONS, INSPECTION,
Propeller Shaft.>
Check the spline and bearing. <Ref. to DS-11,
SPLINES AND BEARING, INSPECTION, Pro-
peller Shaft.>
Check the wheel balance. <Ref. to WT-9,
ADJUSTMENT, Wheel Balancing.>
Check the front wheel alignment. <Ref. to FS-7,
INSPECTION, Wheel Alignment.>
Check the rear wheel alignment. <Ref. to RS-8,
INSPECTION, Wheel Alignment.>
Check the front strut. <Ref. to FS-24, INSPEC-
TION, Front Strut.>
Check the rear shock absorber. <Ref. to RS-14,
INSPECTION, Rear Shock Absorber.>
Check the front drive shaft. <Ref. to DS-29,
INSPECTION, Front Drive Shaft.>
Check the rear drive shaft. <Ref. to DS-34,
INSPECTION, Rear Drive Shaft.>
Check the front hub unit bearing. <Ref. to DS-18,
INSPECTION, Front Hub Unit Bearing.>
Check the rear hub unit bearing. <Ref. to DS-25,
INSPECTION, Rear Hub Unit Bearing.>
Check the wheel balance. <Ref. to WT-9,
ADJUSTMENT, Wheel Balancing.>
Check the front wheel alignment. <Ref. to FS-7,
INSPECTION, Wheel Alignment.>
Check the rear wheel alignment. <Ref. to RS-8,
INSPECTION, Wheel Alignment.>
Check the front strut. <Ref. to FS-24, INSPEC-
TION, Front Strut.>
Check the rear shock absorber. <Ref. to RS-14,
INSPECTION, Rear Shock Absorber.>