How to Replace the Serpentine Belt on a 2018 Subaru Crosstrek (Accessory Drive Belt)
Step-by-step instructions with required tools/parts, belt routing tips, and post-install checks for squeal for 2016, 2018, 2019, 2020, 2021, 2022, 2023, 2024
How to Replace the Serpentine Belt on a 2018 Subaru Crosstrek (Accessory Drive Belt)
Step-by-step instructions with required tools/parts, belt routing tips, and post-install checks for squeal for 2016, 2018, 2019, 2020, 2021, 2022, 2023, 2024
🔧 Crosstrek - Serpentine Belt Replacement
The serpentine belt (also called the accessory drive belt) spins your alternator and A/C compressor. If it’s cracked, squealing, or glazed, replacing it prevents loss of charging and overheating-related problems.
Difficulty Level: Intermediate | Estimated Time: 0.5-1.0 hours
⚠️ Safety & Precautions
- ⚠️ Work on a cool engine; keep hands away from hot parts.
- ⚠️ Key out of ignition; never work near a moving belt.
- ⚠️ Keep fingers clear when releasing the belt tensioner; it is spring-loaded.
- ⚠️ Battery disconnect is not required, but avoid shorting tools on the battery terminals.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 1/4" ratchet
- 6" extension
- Trim clip removal tool
- 14mm box wrench
- Flashlight
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Serpentine belt (accessory drive belt) - Qty: 1
📋 Before You Begin
- Park on level ground, set the parking brake, and open the hood.
- Take a clear photo of the belt routing before removal. This saves lots of frustration.
- If your Crosstrek has an upper air snorkel/duct blocking access, plan to remove it first.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Create working room at the front of the engine
- Use a flashlight to locate the belt path around the pulleys.
- If an intake snorkel/upper duct is in the way, remove it using a 10mm socket, 1/4" ratchet, and 6" extension.
- If plastic clips are used, pop them out with a trim clip removal tool.
Step 2: Relieve belt tension (spring-loaded tensioner)
- Find the belt tensioner (the spring-loaded arm with a pulley).
- Place a 14mm box wrench on the tensioner’s hex/boss and rotate the tensioner to relieve belt tension.
- While holding the tensioner released, slide the belt off one easy-to-reach pulley (usually the alternator pulley) by hand.
- Move slowly—spring force is strong.
Step 3: Remove the old belt
- With the belt now loose, let the tensioner return gently to rest.
- Remove the belt from the remaining pulleys by hand and pull it out of the engine bay.
- Inspect pulleys with a flashlight for wobble or rough spinning by hand.
Step 4: Route the new belt correctly
- Compare the new belt to the old belt length/width before installing.
- Route the new belt around the pulleys following your photo (leave the most accessible pulley for last).
- Make sure the belt ribs sit fully in the ribbed pulleys’ grooves (not riding on an edge).
Step 5: Reapply tension and seat the belt
- Use the 14mm box wrench to rotate the tensioner again to create slack.
- Slip the belt onto the final pulley, then slowly release the tensioner.
- Recheck every pulley with a flashlight: the belt must be centered and fully seated.
- If it’s off by one rib, redo it.
Step 6: Reinstall the intake snorkel/duct (if removed)
- Reinstall the snorkel/duct using the 10mm socket, 1/4" ratchet, and 6" extension.
- Reinstall any push-clips using the trim clip removal tool.
- Torque: If any 10mm bolts were removed, snug them firmly by hand; Subaru does not require high torque here and overtightening can crack plastic.
✅ After Repair
- Start the engine and watch the belt for 15–30 seconds; it should run smoothly with no wandering.
- Listen for squeal or ticking. If present, shut off and recheck belt seating on every pulley.
- After a short drive, do a quick recheck to confirm the belt is still centered.
💰 DIY vs Shop Cost
Shop Cost: ₹3,500-₹8,000 (parts + labor)
DIY Cost: ₹1,200-₹3,000 (parts only)
You Save: ₹2,300-₹5,000 by doing it yourself!
Shop labor rates vary but typically run ₹1,000-₹2,500/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.


















