🔧 Forester - Serpentine Belt Replacement

Your Forester uses one accessory (serpentine) belt to drive key components like the alternator and A/C. Replacing it is mostly about gaining access, releasing the spring-loaded belt tensioner, and installing the new belt on the correct routing.

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

---

⚠️ Safety & Precautions

• 🛑 Work on a cold engine; keep hands clear of fans and pulleys.
• 🛑 Remove the key/fob from the vehicle so the engine can’t be started accidentally.
• 🛑 Do not put fingers between the belt and pulleys while releasing tension.
• 🛑 If you raise the front end for access, support it with jack stands (never only a jack).
• 🛑 Battery disconnect is not required for this job, but keep tools away from the alternator power wire.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3/8" drive ratchet
• 3" extension (3/8" drive)
• 14mm combination wrench
• 14mm socket
• Flat trim clip tool
• Flathead screwdriver
• Flashlight
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Safety glasses
• Mechanic gloves

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Accessory drive belt (serpentine belt) - Qty: 1

---

📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Open the hood and find the belt routing diagram (often on the radiator support/underside of hood).
• Take a clear photo of the belt routing with your phone as a backup.
• If access is tight, raise the front slightly using a floor jack and support with jack stands; use wheel chocks at the rear tires.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove top-side covers/ducting for access

• Remove the engine cover (if equipped) using a 10mm socket and 3/8" ratchet.
• If the plastic intake snorkel/upper duct blocks access, remove its clips using a flat trim clip tool and/or flathead screwdriver, then remove any bolts using a 10mm socket.
• Tip: Keep clips in a cup.

Step 2: Inspect the belt routing and pulleys

• Use a flashlight to confirm the belt routing on each pulley.
• Look for cracked ribs, missing chunks, or glazing (shiny belt surface).
• Spin any easy-to-reach smooth idler/tensioner pulleys by hand (engine OFF); if you hear grinding, plan on replacing that pulley/tensioner too.

Step 3: Relieve belt tension (spring-loaded tensioner)

• Place a 14mm socket (with 3/8" ratchet and extension) or a 14mm combination wrench on the tensioner’s hex/bolt head.
• Slowly rotate the tensioner in the direction that makes the belt go slack. (You’ll feel strong spring resistance.)
• Tip: If it gets tighter immediately, go the other way.

Step 4: Remove the old belt

• While holding the tensioner released with the 14mm wrench or 14mm socket, slip the belt off the easiest-to-reach upper pulley (commonly the alternator).
• Slowly let the tensioner return to its resting position (do not let it snap back).
• Remove the belt fully from the remaining pulleys by hand.

Step 5: Install the new belt (match the routing)

• Compare the new belt to the old belt for length and rib count before installing.
• Route the new belt around all pulleys except the last easy upper pulley, using your routing diagram/photo as the guide.
• Make sure the ribbed side of the belt is seated into ribbed pulleys, and the smooth side rides on smooth pulleys.

Step 6: Re-apply tension and seat the belt

• Relieve tension again using the 14mm socket or 14mm combination wrench.
• Slip the belt onto the last pulley, then slowly release the tensioner.
• Do a final check with a flashlight: the belt must be centered on every pulley and fully seated in all grooves.

Step 7: Reinstall removed ducting/covers

• Reinstall the intake ducting/snorkel using a 10mm socket and any clips using a flat trim clip tool.
• Reinstall the engine cover using a 10mm socket.

---

✅ After Repair

• Start the engine and watch the belt for 30–60 seconds. It should run smooth with no hopping or squealing.
• Turn A/C on and off and listen for belt noise changes.
• Shut the engine off and re-check belt seating with a flashlight.
• If you hear persistent squeal, re-check routing and that the ribs are fully in the grooves.

---

💰 DIY vs Shop Cost

Shop Cost: $150-$280 (parts + labor)

DIY Cost: $25-$60 (parts only)

You Save: $125-$220 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 hours.

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.