Parts for your 1999 Subaru Forester-Drive belt tensioner

1999 Subaru Forester drive-belt tensioner: what’s fitted and what isn’t

For the 1999 Subaru Forester (SF series, EJ20/EJ25), an automatic accessory drive-belt tensioner isn’t fitted. The factory setup uses two separate V-ribbed belts with manual adjustment: the alternator/power-steering belt is tensioned via the alternator’s pivot and adjuster bolts, and the A/C belt is tensioned with a dedicated idler pulley and jack screw. The only true “tensioner” on this model is the hydraulic timing-belt tensioner inside the timing cover, which isn’t part of the external accessory drive.

This isn’t a parts-catalogue quirk—it's how Subaru designed the SF Forester. Technical references back it up: the Subaru Factory Service Manual for the 1999 Forester describes belt adjustment procedures using the alternator bracket and the A/C idler’s jack bolt, with no mention of a spring-loaded accessory tensioner. Haynes’ Subaru Legacy/Forester manual for this era outlines the same method, and major belt suppliers’ application catalogues list belts and idler pulleys, but no accessory “tensioner assembly” for 1999 Forester models.

Why no accessory tensioner? Subaru’s late-’90s layout predates the switch to a single serpentine belt with an automatic tensioner seen on later models. The twin-belt, manual-adjust setup keeps parts count and cost down, and it’s dead simple to service with basic tools. The trade-off is that belt tension is a maintenance item: it needs checking and adjusting as part of regular servicing, especially after fitting new belts.

What should Forester owners and techs do at service time? Inspect both accessory belts for glazing, cracking, fraying or contamination, spin the A/C idler pulley and feel for roughness or play, and listen for squeals at cold start that hint at a loose or glazed belt. Adjust tension by loosening the relevant lock bolts, turning the adjuster (alternator) or jack screw (A/C idler) to the factory spec, then re-tighten lock bolts. Re-check tension after the first few hundred kilometres on new belts as they bed in. If the A/C idler pulley is noisy, replace it—it’s a common wear item on these cars. Remember, the timing-belt tensioner is a different component altogether and is serviced with the timing belt, not with the accessory belts.

• Technical sources referenced:
  • Subaru Forester 1999 Factory Service Manual – Engine/Mechanical: Drive Belts and A/C Belt Adjustment
  • Haynes Manual: Subaru Legacy & Forester 1990–1999 – Drive belt adjustment procedures
  • Major belt supplier application catalogues for 1999 Forester (listing belts and idler, no accessory tensioner assembly)

FAQs

Does a 1999 Subaru Forester have an accessory drive-belt tensioner?
No. It uses manual adjustment for the alternator/power-steering belt and a separate adjustable idler for the A/C belt. The only “tensioner” on the car is the hydraulic timing-belt tensioner, which is unrelated to the external accessory belts.

How do you adjust the accessory belts on a 1999 Forester?
For the alternator belt, loosen the alternator’s lock and pivot bolts, turn the adjuster bolt to set the correct tension, then re-tighten. For the A/C belt, loosen the idler’s lock nut, turn the jack screw to tension the belt, and lock it back up. Follow the service manual spec and re-check after a short run-in.

What should be replaced if there’s belt squeal but no tensioner?
Inspect and, if needed, replace the belts themselves, the A/C idler pulley (a common culprit when noisy), and check pulley alignment and the crank pulley/harmonic balancer condition. Proper adjustment and fresh belts fix most squeals.