Parts for your 2017 Subaru Forester-Harmonic balancers

2017 Subaru Forester harmonic balancer: what it does and when to replace it

Based on Subaru workshop information for the 2017 model year Forester (FB25 2.5i and FA20F XT), the crankshaft pulley is a damper-type unit that incorporates an elastomer to control torsional vibration. Subaru’s service manual sections for “Crankshaft Pulley/Damper” and OEM parts catalogues list it as a balancer/damper assembly, and leading component manufacturers (e.g., Dayco, Gates) catalogue direct replacement harmonic balancers for these engines. So yes, a harmonic balancer is fitted to the 2017 Subaru Forester.

On this boxer-four, the balancer’s job is to smooth out crankshaft twist created each time a cylinder fires. That damping protects the timing chain, oil pump, bearings and front-end accessories from stress, cuts belt noise, and helps the engine feel more refined. The outer ring you see driving the belt is bonded to the hub through rubber, that rubber is the magic bit that soaks up vibration.

It’s not a high-maintenance item, but it does deserve a look during routine servicing. A quick visual and run-up check can save a world of grief if the rubber starts to let go.

• Common red flags: pulley wobble at idle, chirping or squealing belt, visible cracks or separation in the rubber layer, unexplained charging or A/C performance drops, and new vibrations around certain revs.
• Inspection tips: with the engine off, look for rubber bulging, cracking or shiny slip marks, with the engine idling, sight the pulley for any lateral run-out.

If replacement’s on the cards, stick with quality OEM or equivalent. Lightweight underdrive pulleys can upset damping and may increase NVH or wear on chains and bearings. A proper crank-holding tool is a must, follow the factory torque/angle spec for the crank bolt and don’t install with a rattle gun. Never pry on the outer ring—use the correct puller points. It’s smart to fit a fresh drive belt if the old one’s glazed or has done big kilometres.

There’s no fixed kilometre interval for swapping the balancer, most are changed only when there’s damage, rubber deterioration, or after an oil leak has soaked the elastomer. As a guide, start giving it extra attention beyond 100,000–120,000 km or if the vehicle sees lots of heat, towing, or dusty work.

Popular questions

Does every 2017 Forester—2.5i and XT—have a harmonic balancer?
Yes. Both the FB25 (2.5i) and FA20F (XT) engines use a crankshaft pulley with an integrated torsional damper. Subaru service documentation and parts catalogues list the assembly for each variant.

Is it safe to drive if the harmonic balancer is wobbling?
Not recommended. A failing damper can shed the outer ring, throw the belt, overheat the engine, or stress the timing drive. If there’s wobble or rubber separation, park it and arrange repair.

What else should be replaced with the balancer?
Often just the drive belt if worn, and any leaking front crank seal that may have contaminated the rubber. Replace the crank bolt if specified by Subaru and always use the correct torque-and-angle procedure.