2020 Subaru Crosstrek: Serpentine Belt

Quick Answer: 2020 Crosstrek Serpentine Belt Specifications

For all 2020 Subaru Crosstrek models equipped with the 2.0L non-hybrid engine, here are the key part numbers and specifications for the serpentine belt and its related components.

• Belt Length & Rib Count: 85.8 inches (2180mm), 6-rib
• OEM Subaru Belt Part Number: 809221280
• Aftermarket Belt Cross-References: Gates K060858, Dayco 5060860, Continental 4060860
• Automatic Tensioner Assembly Part Number: Subaru PN 23769AA05A
• Idler Pulley Part Number: Subaru PN 23770AA09A

Disclaimer: Part numbers can change based on production date and supplier. Always confirm part compatibility by using your vehicle's VIN with your parts supplier before purchasing.

Belt Routing

The 2020 Subaru Crosstrek uses a single serpentine belt to drive all its engine accessories. The FB20 2.0L engine in this model has electric power steering and a water pump driven by the timing assembly, so the accessory belt path is relatively simple.

Crucial Tip: Before you loosen the belt, take a clear photograph of the belt's path from a couple of angles. A simple photo can save you a major headache during reassembly.

The belt is routed as follows:

1. Starts at the main Crankshaft Pulley at the bottom center of the engine.
2. Wraps up and around the Air Conditioning Compressor pulley on the lower passenger side.
3. Goes up to the smooth Idler Pulley on the upper passenger side.
4. Crosses over the top of the engine to the Alternator pulley on the upper driver's side.
5. Travels down to the Automatic Tensioner pulley.
6. Finally, returns to the Crankshaft Pulley.

How to Replace the Serpentine Belt

Replacing the serpentine belt on a 2020 Crosstrek is a manageable task for a DIYer with the right tools. The primary tool you will need is a 14mm wrench or socket on a long-handled ratchet or breaker bar to release the belt tension.

1. Safety First: Ensure the vehicle is parked on a level surface, in Park, with the parking brake engaged. Wait for the engine to cool completely.
2. Locate the Tensioner: The automatic belt tensioner is located between the alternator and the crankshaft pulley. It has a 14mm bolt head on the front of the pulley which is used to pivot the assembly.
3. Release Tension: Place your 14mm wrench or socket on the tensioner pulley bolt. Rotate the tensioner clockwise (towards the passenger side) to release the tension on the belt. The spring is strong, so it will require significant force.
4. Remove the Old Belt: While holding the tensioner in the released position, carefully slip the old belt off one of the smooth, non-lipped pulleys, like the idler pulley.
5. Verify Parts: Compare the new belt with the old one to ensure the length and rib count match perfectly.
6. Route the New Belt: Following your photo or the diagram above, carefully route the new belt around all the pulleys, leaving one of the smooth pulleys (like the idler) for last.
7. Final Installation: Release the tensioner again by rotating it clockwise, and carefully slide the belt over the final pulley. Once the belt is in place on all pulleys, slowly and carefully release the tensioner, ensuring the belt seats correctly into the grooves on each ribbed pulley.
8. Final Check: Double-check that the belt is correctly aligned in all pulley grooves. An incorrectly seated belt will shred itself almost immediately upon engine start-up. Start the engine and listen for any unusual noises and watch the belt path to ensure smooth operation.

Replacement Interval

Subaru does not specify a strict mileage-based replacement interval for the serpentine belt in the 2020 Crosstrek's maintenance schedule. Instead, it follows an "inspect, and replace as needed" policy during routine service, typically every 30,000 miles. As a general rule of thumb, most serpentine belts have a realistic service life of 60,000 to 100,000 miles. If your vehicle is approaching this mileage range, it's wise to replace the belt proactively to avoid a breakdown.

Signs of a Failing Belt or Tensioner

Your serpentine belt and its tensioner will usually provide audible or visual cues that they are nearing the end of their service life. Ignoring these signs can lead to the belt breaking, which will cause an immediate loss of alternator function (and a dead battery) and air conditioning, potentially leaving you stranded.

• Squealing or Chirping Noises: This is the most common symptom. The noise may be most prominent during cold starts, when turning the steering wheel, or when the A/C compressor kicks on.
• Visible Wear: Inspect the belt for cracks, fraying, glazing (a shiny, smooth appearance on the ribbed side), or missing chunks of ribbing.
• Tensioner Noise: A worn-out tensioner pulley bearing will often make a grinding or chirping sound that is constant while the engine is running.
• Battery Light: If the belt is slipping badly or breaks, the alternator will stop spinning, and the battery warning light will illuminate on your dashboard.

Keeping the serpentine belt in good condition is crucial for your Crosstrek's reliability. If you're not comfortable performing this service yourself, Repairius can help.

Find a trusted shop on Repairius.