Parts for your 2004 Subaru Forester-Drive belt pulley

2004 Subaru Forester drive-belt pulley — purpose, care and when to replace

Based on technical documentation, a drive-belt pulley is absolutely relevant to the 2004 Subaru Forester. The Subaru factory service manual for MY04 Forester (H4 SOHC and H4 DOHC Turbo sections covering “Drive Belt” and “Pulley”), Subaru’s Technical Information System, and Australian application guides from Gates and Dayco all show the EJ-series engines running accessory drive belts over multiple pulleys: the crankshaft (harmonic balancer) pulley, alternator pulley, A/C compressor pulley, power steering pulley, plus idler and tensioner pulleys.

On this Forester generation, the accessory drive typically uses two multi-rib belts rather than a single long serpentine. One belt runs the alternator and power steering, the other runs the A/C compressor. The pulleys guide and transmit crankshaft power to these accessories, while the crank pulley also contains a rubber damper to absorb torsional vibration. Healthy pulleys mean steady charging, light steering effort and cold air-con, worn pulleys bring noise, belt wear and poor accessory performance.

Routine servicing should include quick checks every 10–15,000 km or at each oil service: look for belt glazing, cracking or fraying, watch the pulleys at idle for wobble, listen for chirps or growls, and feel idler/tensioner pulleys spun by hand (engine off) for roughness. As a rule of thumb, many workshops replace accessory belts around 60–100,000 km or 4–6 years, and renew idler/tensioner pulleys at the same time or if any noise/play is present. The crank pulley should be inspected for rubber separation or runout, replace it if the damper is delaminating or the pulley wobbles.

• Common warning signs: belt squeal on start-up, chirp that changes with revs, visible pulley wobble, black belt dust, burnt-rubber smell, or a tensioner arm that flickers.
• Service tips: release belt tension fully before removal, check pulley alignment with a straightedge, spin and side-load idlers by hand to feel for grittiness, and torque fasteners to the factory specs from the Subaru service manual.

Quality matters. For the 2004 Forester, choose OEM or reputable aftermarket pulleys and replace any suspect tensioner as a unit. While timing and accessory systems are separate, many owners bundle accessory belt and pulley work with timing-belt servicing to save labour when the front of the engine is already opened up.

FAQ

Does the 2004 Forester use one serpentine belt or two?
Most 2004 Foresters with EJ engines use two ribbed belts: one for alternator/power steering and one for the A/C. Each runs across its own set of pulleys and an adjuster/tensioner. Some variants may differ slightly, but the pulley-driven accessory layout is consistent.

How can someone tell if a pulley is failing versus just the belt?
If the noise continues briefly after the belt is removed, the pulley bearing is likely rough. Other clues are pulley wobble, gritty feel when spun by hand, blueing/heat marks, or metal dust around the bearing. If only the belt is glazed or cracked but pulleys feel smooth and tight, the belt may be the sole culprit.

Should the crankshaft (harmonic balancer) pulley be replaced preventatively?
It isn’t a scheduled item, but it should be replaced if the rubber damper is cracking or the pulley shows runout. Always use quality parts and correct bolt torque, a failing balancer can cause belt misalignment and accessory noise.