Parts for your 2010 Subaru Tribeca-Drive belt tensioner

2010 Subaru Tribeca Drive-Belt Tensioner

Based on technical sources, the 2010 Subaru Tribeca (EZ36 3.6L H6) is fitted with an automatic accessory drive-belt tensioner. This is documented in the Subaru Factory Service Manual for MY2010 Tribeca (Engine/Mechanical front drive section) and supported by the Subaru electronic parts catalogue, which lists a “belt tensioner assembly” for the EZ36 accessory drive. Major aftermarket catalogues from Gates and Dayco also list an automatic belt tensioner for the 2008–2014 Tribeca/EZ36. Note: the A/C runs a separate stretch-fit belt on many EZ36 applications and does not use a separate tensioner.

The drive-belt tensioner on a 2010 Subaru Tribeca keeps the serpentine belt tight as the engine runs, taking up slack as the belt wears and as loads change. On the EZ36 H6, that belt drives essentials like the alternator, water pump and power steering. The spring-loaded tensioner constantly applies the right force, reducing belt slip, squeal and premature wear. It also helps keep the belt tracking true across the pulleys, which is key for quiet running and reliable charging and cooling.

For servicing, it’s smart to inspect the tensioner at each service or at least every 15,000–20,000 km. They generally last a long time, but it’s common to replace the tensioner around the time the second serpentine belt is due, or sooner if there are symptoms. Listen for chirps or rattles at idle, look for a wobbly or misaligned tensioner pulley, check for hydraulic damper leakage (if equipped), and watch the belt for frayed edges or glazing. An intermittent battery warning light, heavy steering at low revs, or belt slap on start-up can all point to a lazy or seized tensioner.

Replacement is straightforward for a trained tech: use the tensioner’s square drive or hex boss to relieve tension, slip the old belt off, spin the pulley to feel for roughness, then swap the tensioner if there’s play, noise, binding or leakage. Always confirm the correct belt routing diagram under the bonnet or from the service manual, and torque the fasteners to spec. If the A/C stretch belt is being replaced, a special installation tool is usually required, there’s no separate tensioner for that belt. After fitting, run the engine, recheck belt tracking, and listen for any odd noises. Using quality OEM-equivalent parts and replacing the belt and tensioner as a matched job can save time and avoid repeat visits. It’s a tidy bit of preventative maintenance that keeps the Tribeca happy on school runs and long Kiwi or Aussie road trips alike.

• Service tip: inspect each service, replace on condition or around 150,000–200,000 km.
• Watch-outs: noise, belt wander, visible pulley wobble, damper oil seepage.
• Note: A/C belt is stretch-fit, no separate tensioner.

Popular questions about 2010 Subaru Tribeca drive-belt tensioners

How long does the belt tensioner usually last on a 2010 Tribeca?
Many last well past 150,000 km, but lifespan depends on climate, belt condition and accessory loads. If the pulley bearing gets noisy, the arm wobbles, or the damper leaks, it’s time. Replacing the tensioner when fitting a new serpentine belt (especially the second belt) is good practice.

What are the common symptoms of a failing tensioner?
Squeaks or chirps on cold start, fluttering belt, visible pulley misalignment, or a flickering battery light are common. You might also feel intermittent heavy steering at idle if the belt is slipping. Any grinding from the pulley or oil seepage from the tensioner body means replacement is due.

Do I need special tools to change the belt or tensioner?
For the main serpentine belt and tensioner, a standard socket set and a breaker bar for the tensioner boss or square drive usually do the job. For the A/C stretch belt, a specific stretch-belt installation tool is recommended, as there’s no tensioner on that circuit.