2017 Toyota Highlander Serpentine Belt Routing & Length

Quick answer

• Belt Length: Approximately 2260mm (89 inches)
• Rib Count: 6-rib
• OEM Belt PN: Toyota 90916-A2002
• Aftermarket Cross-references:
  • Gates K060890
  • Dayco 5060890
  • Continental Elite 4060890
• Auto-Tensioner PN: Toyota 16620-31012 (or similar, verify for specific engine)
• Idler Pulley PN: Toyota 16603-31030 (or similar, verify for specific engine)

Belt Routing

The 2017 Toyota Highlander, commonly equipped with the 3.5L V6 engine (2GR-FE), utilizes a single serpentine belt to drive all its accessories. Before you even think about removing the old belt, take a clear, well-lit photo of the existing belt routing! This will be your most valuable reference during reinstallation.

Here's a step-by-step text-based description of the routing path:

1. Crankshaft Pulley: The belt originates from the bottom-most, largest pulley – the crankshaft pulley. This is the main drive pulley, powered directly by the engine.
2. A/C Compressor: From the crankshaft pulley, the belt typically travels upward and to the right (when facing the engine from the front of the vehicle) to wrap around the air conditioning compressor pulley.
3. Idler Pulley (lower): After the A/C compressor, the belt may pass over or under a stationary idler pulley, which helps guide the belt and maintain proper tension.
4. Alternator: The belt then proceeds upward to the alternator pulley, which is usually located high on the engine, often on the passenger side.
5. Power Steering Pump: From the alternator, the belt generally moves across to the power steering pump pulley, typically situated below or to the side of the alternator.
6. Water Pump: The belt often continues from the power steering pump to the water pump pulley, which might be located in the center or slightly to one side of the engine's front.
7. Tensioner Pulley: Finally, the belt goes around the auto-tensioner pulley, which provides the necessary constant tension to keep the belt operating correctly. The tensioner is usually spring-loaded and provides an access point for a serpentine belt tool or a breaker bar to release tension for belt removal and installation.

Note on Engine Options: While this routing is common for the 3.5L V6, some Highlanders may have different engine configurations (e.g., 2.7L 4-cylinder in some trims or markets). Always verify the specific routing for your exact engine. The principle of photographing the old belt remains critical regardless of the engine.

How to replace the serpentine belt

Replacing the serpentine belt on your 2017 Toyota Highlander is a manageable DIY task for those with some mechanical aptitude. You'll primarily need a serpentine belt tool or a standard 3/8-inch breaker bar and socket set.

1. Locate the Tensioner: Identify the auto-tensioner pulley. It will have a square drive hole (usually 3/8-inch or 1/2-inch) designed to accept a wrench or breaker bar.
2. Release Tension: Insert your serpentine belt tool or breaker bar into the square drive hole of the tensioner. Apply steady, downward (or sometimes upward, depending on the tensioner's orientation) pressure to pivot the tensioner and relieve tension on the belt.
3. Remove Old Belt: While holding tension, carefully slip the old belt off one of the easier pulleys (like the alternator or power steering pump). Once it's off a pulley, you can release the tensioner and remove the belt completely from all pulleys.
4. Route New Belt: Refer to the photo you took earlier and the routing diagram above. Carefully route the new belt around all pulleys except for the tensioner or an easily accessible pulley.
5. Install on Tensioner: Re-apply pressure to the tensioner with your tool. While holding it open, slip the new belt over the last pulley. Ensure the belt is properly seated in all the grooves of every pulley.
6. Verify Seating: Release the tensioner slowly. Double-check that the belt is perfectly aligned in all the grooves of every pulley. Rotate the crankshaft by hand (if possible and safe to do so with the engine off) a full revolution to ensure the belt is properly seated and hasn't jumped any grooves.

Replacement interval

Toyota generally recommends inspecting the serpentine belt at regular service intervals, typically every 30,000 miles or 3 years. Replacement is usually suggested around 60,000 to 100,000 miles, or sooner if signs of wear are observed. However, driving conditions and climate can affect its lifespan. It’s always best to consult your owner's manual for the most accurate manufacturer recommendations for your specific vehicle.

Signs of a failing belt or tensioner

Don't wait for a complete belt failure – it can leave you stranded! Pay attention to these warning signs:

Failing Serpentine Belt:

• Squealing or Chirping Noises: This is one of the most common signs. A slipping or worn belt will often create a loud squealing sound, especially on cold starts, during hard acceleration, or when turning the steering wheel (if equipped with hydraulic power steering).
• Cracks or Fraying: Visually inspect the belt. Look for cracks, especially on the ribbed side, fraying edges, chunks missing, or a glazed (shiny) appearance. Glazing indicates a hardened, less flexible belt.
• Loss of Accessory Function: Since the belt drives multiple accessories, a failing belt can lead to a non-charging battery (alternator), lack of A/C cooling (A/C compressor), hard steering (power steering pump), or engine overheating (water pump).
• Shredded or Missing Ribs: A severely worn belt may start to shed material or have entire ribs missing, which can drastically reduce its contact area and effectiveness.

Failing Auto-Tensioner:

• Excessive Belt Slack: A worn tensioner may not apply enough pressure, leading to a visibly loose or flopping belt. You might see the belt vibrate excessively.
• Grinding or Squealing from Tensioner: The bearings within the tensioner pulley can wear out, causing a grinding, rattling, or squealing noise directly from the tensioner assembly.
• Tensioner Arm Movement: While the engine is running, a healthy tensioner arm should remain relatively steady. If it's bouncing or vibrating excessively, it could indicate a failing tensioner.
• Visible Rust or Damage: Inspect the tensioner body and pivot points for rust, corrosion, or physical damage.

If you observe any of these symptoms, it's crucial to have your serpentine belt and tensioner inspected by a qualified technician promptly to avoid further damage or an inconvenient breakdown.

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