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2010 Subaru Outback
2005 - 2011 Subaru Outback
Flat 4 2.5L
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  • Guides
  • /
  • Subaru Outback
  • /
  • 2005 to 2011
  • /
  • How to Replace the Serpentine (Accessory Drive) Belts on a 2005-2011 Subaru Outback (Engine: Flat 4 2.5L)
How to Replace the Serpentine Belt on a 2010 Subaru Outback

How to Replace the Serpentine Belt on a 2010 Subaru Outback

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Glasses
Nitrile
Nitrile
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10mm
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or (3/8")
10mm
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How to Replace the Serpentine (Accessory Drive) Belts on a 2005-2011 Subaru Outback (Engine: Flat 4 2.5L)

Step-by-step alternator/power steering and A/C belt replacement with tools, routing tips, and torque specs

How to Replace the Serpentine (Accessory Drive) Belts on a 2005-2011 Subaru Outback (Engine: Flat 4 2.5L)

Step-by-step alternator/power steering and A/C belt replacement with tools, routing tips, and torque specs for 2005, 2006, 2007, 2008, 2009, 2010, 2011

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Orion

đź”§ Outback - Serpentine Belt Replacement

On your Outback, the “serpentine belt” term is often used loosely—many 2.5L setups use two accessory drive belts: one for alternator/power steering and one for A/C. Replacing them is mainly about loosening the adjusters, swapping the belt(s), then setting correct tension so you don’t get squeal or premature bearing wear.

Difficulty Level: Beginner | Estimated Time: 0.5-1.5 hours


⚠️ Safety & Precautions

  • ⚠️ Work on a cool engine; keep hands clear of the radiator fans.
  • ⚠️ Remove the key and make sure the engine cannot start while your fingers are near pulleys.
  • ⚠️ If you jack the front up for access, support with jack stands on solid ground.
  • ⚠️ Avoid over-tightening belts—too tight can damage alternator/power steering bearings.
  • ⚠️ Battery disconnect is not required, but it’s safer if you’ll be near the alternator wiring: use a 10mm wrench to remove the negative terminal.

đź”§ Required Tools

You'll need the following tools for this repair:

  • Safety glasses
  • Mechanic gloves
  • Flashlight
  • 10mm wrench
  • 10mm socket
  • 12mm socket
  • 14mm socket
  • 3/8" ratchet
  • 3/8" breaker bar
  • Torque wrench (10-80 ft-lbs)
  • Trim clip tool
  • Floor jack (rated 3-ton minimum)
  • Jack stands (rated 3-ton minimum)
  • Wheel chocks

🔩 Required Parts

HowToo sells all the parts you need for this repair:

  • Alternator/Power steering drive belt - Qty: 1
  • A/C drive belt - Qty: 1

đź“‹ Before You Begin

  • Park on level ground, transmission in neutral, and set the parking brake.
  • Chock the rear wheels using wheel chocks.
  • If you want extra room, raise the front and support with jack stands using a floor jack.
  • Take a quick photo of belt routing.

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Get access to the front of the engine

  • Open the hood and use a flashlight to locate the belts and pulleys at the front of the engine.
  • If your air intake snorkel blocks access, remove its clips using a trim clip tool and any bolts using a 10mm socket.

Step 2: Identify which belt(s) you’re replacing

  • The alternator/power steering belt runs around the alternator and power steering pump pulleys.
  • The A/C belt runs lower around the A/C compressor and an idler pulley.
  • If one belt is cracked, replace both.

Step 3: Loosen the alternator (alternator/power steering belt)

  • Use a 12mm socket to loosen (do not remove) the alternator lock bolt.
  • Use a 12mm socket to loosen (do not remove) the alternator pivot bolt.
  • Use a 10mm socket to turn the alternator adjuster screw counterclockwise until the belt is loose.

Step 4: Remove and install the alternator/power steering belt

  • Slip the old belt off the pulleys by hand. If it’s stubborn, use a breaker bar to slightly relieve tension by backing off the 10mm socket adjuster more.
  • Route the new belt over the pulleys in the same path as the old belt.
  • Use the 10mm socket on the adjuster screw to tension the belt until it has about 1/4"-3/8" (6-10mm) of deflection at the longest straight span using firm finger pressure.
  • Tighten the alternator bolts using a torque wrench:
    • Alternator pivot bolt: Torque to 44 Nm (32 ft-lbs)
    • Alternator lock bolt: Torque to 23 Nm (17 ft-lbs)

Step 5: Loosen the A/C belt idler (A/C belt)

  • Locate the A/C belt idler pulley (lower front area).
  • Use a 12mm socket to loosen the idler lock bolt.
  • Use a 10mm socket to turn the idler adjuster screw counterclockwise to relieve belt tension.

Step 6: Remove and install the A/C belt

  • Slip the old A/C belt off the pulleys by hand.
  • Route the new A/C belt onto the crank and A/C compressor pulleys.
  • Use the 10mm socket on the adjuster screw to tension the belt until it has about 1/4"-3/8" (6-10mm) of deflection at the longest straight span using firm finger pressure.
  • Tighten the idler bolts using a torque wrench:
    • Idler lock bolt: Torque to 39 Nm (29 ft-lbs)

Step 7: Double-check alignment and tension

  • Use a flashlight to confirm each belt is fully seated in every pulley groove (not riding on an edge).
  • Spin-check by hand: with engine off, rotate a pulley carefully to confirm the belt tracks straight.

Step 8: Reinstall anything you removed

  • Reinstall the intake snorkel/clips using a trim clip tool and 10mm socket.
  • If you disconnected the battery, reconnect the negative terminal using a 10mm wrench.
  • If you lifted the vehicle, lower it safely using a floor jack and remove the jack stands.

âś… After Repair

  • Start the engine and listen for belt squeal or slapping.
  • Turn on electrical loads (headlights, rear defogger) and confirm no squeal.
  • Turn the steering wheel lock-to-lock and confirm the power steering feels normal (no squeal).
  • Turn the A/C on and confirm the A/C belt runs smoothly.
  • Recheck belt tension after a short 10-15 minute drive; belts can “seat” and loosen slightly.

đź’° DIY vs Shop Cost

Shop Cost: $180-$350 (parts + labor)

DIY Cost: $30-$90 (parts only)

You Save: $150-$260 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.2 hours.


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Guide for Serpentine Belt replace for these Subaru vehicles

Year Make ModelSub ModelEngineBody Style
2011 Subaru Outback-Flat 4 2.5L-
2010 Subaru Outback-Flat 4 2.5L-
2009 Subaru Outback-Flat 4 2.5L-
2008 Subaru Outback-Flat 4 2.5L-
2007 Subaru Outback-Flat 4 2.5L-
2006 Subaru Outback-Flat 4 2.5L-
2005 Subaru Outback-Flat 4 2.5L-
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