2010 Subaru Impreza Owner's Manual - Page 339

11-20 Maintenance and service Drive belts Check the deflection of the front side belt and if there is any looseness, cracks, wear or unusual noise on the front side belt, contact your SUBARU dealer. Continuing to use the vehicle with the belt outside of the specification may cause the engine to malfunction and the above components to malfunction. To check the deflection of the front side belt, place a straightedge (ruler) across two adjacent pulleys (alternator pulley and crank pulley) and apply a force of 22 lbf (98 N, 10 kgf) midway between the pulleys by using a spring scale. The belt deflection should be the amount specified. If the front side belt is loose, cracked or worn, contact your SUBARU dealer. in (mm) Deflection New belt A 0.28 - 0.35 (7.0 - 9.0) Used belt 0.35 - 0.43 (9.0 - 11.0) Manual transmission oil & Checking the oil level 1) 2) 3) 4) 5) 6) A) Power steering oil pump pulley Front side belt Alternator pulley Air conditioner compressor pulley Rear side belt Crank pulley 22 lbf (98 N, 10 kgf) Non-turbo models 1) Yellow handle CAUTION The front side belt, which runs in conjunction with the following components, must be used within the specified deflection. . Power steering oil pump pulley . Alternator pulley . Crank pulley The rear side belt is a stretch-type belt, therefore the deflection does not need to be checked. If there are cracks or wear confirmed on the belts and a squeaking noise is heard from them, contact your SUBARU dealer. Turbo models except WRX STI