Parts for your 2017 Subaru Exiga-Drive belt tensioner

2017 Subaru Exiga drive-belt tensioner — what it does and when to service it

Yes, a drive-belt tensioner is used on the 2017 Subaru Exiga (including the Crossover 7). On the FB-series engine fitted to this model, the main auxiliary/serpentine belt that drives the alternator runs with an automatic spring-loaded tensioner. The separate A/C compressor uses a stretch-fit belt with no tensioner. This layout is confirmed by Subaru’s factory service information for FB engines and by reputable belt manufacturers’ technical guides for FA/FB applications.

The drive-belt tensioner’s job is to keep the alternator belt at the right tension as the belt wears and as loads change. That steady tension helps the belt grip quietly, prevents slip under heavy electrical load (think lights, demister and fans all on), and reduces shock loads through the front-end accessory drive. It also protects bearings in the alternator and idlers by keeping the belt tracking straight.

As part of routine servicing in Australia and New Zealand conditions, it’s smart to have the belt and tensioner inspected at each service and more closely every 40–60,000 kilometres. Look and listen for squeaks at cold start, chirps on quick rev blips, visible pulley wobble, the arm jittering, or cracking and glazing on the belt. If the pulley bearing feels rough or there’s hydraulic/spring weakness (arm at the stop, poor return), the tensioner should be replaced as an assembly. Belts and tensioners age faster in hot summers, dusty roads and coastal air, so don’t be shy about earlier replacement if there’s noise or wear.

When replacing the alternator belt, the technician will use the hex/drive on the tensioner to unload it, fit the new belt, and re-seat the tensioner smoothly. Always follow factory torque specs for the tensioner fasteners and use a quality belt from a recognised brand. If the A/C belt is due, remember it’s a single-use stretch-fit type: the old one is cut off and the new one installed with the correct installation tool—there’s no adjustment because there’s no tensioner on that circuit.

Practical tip: if the alternator belt is being renewed and the tensioner shows any hint of bearing noise or weak spring action, replace both together to avoid a second trip under the bonnet. It’s a simple, preventative bit of maintenance that keeps charging performance reliable and the cabin quiet.

Technical sources referenced: Subaru factory service information for FB-series engines (drive belt/tensioner sections), Subaru parts catalogues listing the auxiliary belt tensioner assembly for FB applications, and Gates/Dayco technical bulletins noting stretch-fit A/C belts on FA/FB engines (no A/C belt tensioner).

• Common signs it’s time: squeal or chirp, belt edge fray, shiny glazing, pulley wobble, or intermittent battery light under load.
• Service habit: inspect at every service, plan belt and tensioner together around major mileage or sooner if noisy.

Popular questions

Does the 2017 Subaru Exiga actually have a belt tensioner?
Yes. The main auxiliary belt that drives the alternator uses an automatic tensioner. The A/C compressor runs a separate stretch-fit belt that doesn’t use a tensioner, which is why some owners only hear about “no tensioner” in A/C belt discussions.

How often should the drive-belt tensioner be replaced?
There’s no fixed time, it’s condition-based. Have it checked at each service and expect it to last well past 100,000 km in normal use. Replace it if there’s bearing noise, weak spring action, visible misalignment, or recurring belt noise even with a new belt.

Can a home mechanic replace the tensioner?
If they’re comfortable with belt routing and have the right tools to unload the tensioner safely, yes. Always follow factory procedures, double-check routing, and torque fasteners correctly. The A/C stretch belt needs the proper installer tool and should not be pried on.