2019 Honda Odyssey Serpentine Belt Guide

Quick Answer

Here are the essential part numbers and specifications for replacing the serpentine belt on a 2019 Honda Odyssey, which comes equipped with the 3.5L V6 (J35Y6) engine.

• Belt Length & Rib Count: 85.5 inches (2175mm), 7-rib
• OEM Belt Part Number: Honda 31110-6A0-A01
• Aftermarket Belt Cross-References:
  • Gates: K070855
  • Dayco: 5070855
  • Continental: 4070855
• Automatic Tensioner Assembly Part Number: Honda 31170-6A0-A01 (Aftermarket examples: Gates 39420, Dayco 89823)
• Idler Pulley Part Number: Honda 31190-RLV-A01 (Aftermarket examples: Gates 36173, Dayco 89163)

Disclaimer: Always verify part numbers with your VIN at your local dealer or parts supplier before purchasing to ensure 100% compatibility.

Belt Routing

The serpentine belt, also known as a multi-rib or V-ribbed belt, drives all the engine's accessories off a single loop. Proper routing is critical for the function of the alternator, A/C compressor, power steering pump, and water pump.

Before you remove the old belt, we strongly recommend taking a clear photograph of the existing belt routing with your smartphone. This simple step can save you a significant amount of time and frustration during reassembly.

For the 2019 Honda Odyssey's 3.5L V6 engine, the belt follows this specific path:

1. Starts at the Crankshaft Pulley (the largest, lowest pulley).
2. Wraps up and around the Air Conditioning (A/C) Compressor pulley.
3. Goes down and under the smooth Idler Pulley.
4. Travels up to the Alternator pulley at the top of the engine.
5. Routes over to the Power Steering Pump pulley.
6. Goes down to the Water Pump pulley.
7. Finally, loops around the Automatic Tensioner pulley, which applies pressure to the back (smooth side) of the belt to maintain proper tension.

How to Replace the Serpentine Belt

Replacing the belt is a manageable task for a DIYer with the right tool. The key is releasing the spring-loaded automatic tensioner.

You will need a serpentine belt tool, which is a long, thin ratchet with various socket and crow's foot attachments. Alternatively, a long 3/8-inch drive breaker bar can often fit into the square opening on the tensioner body.

1. Locate the Tensioner: The automatic tensioner is the component with a pulley that presses against the backside of the belt. It has a square 3/8" drive hole or a hex-shaped lug cast into it.
2. Release Tension: Fit your serpentine belt tool or breaker bar into the tensioner. Rotate the tool (typically clockwise on this Honda engine) to release the belt's tension. You will feel significant spring resistance.
3. Remove Old Belt: While holding the tensioner in the released position, use your other hand to slip the belt off one of the smooth pulleys, like the idler or tensioner pulley itself. Slowly release the tensioner back to its resting position. You can now fully remove the old belt.
4. Install New Belt: Following your photograph or the path described above, carefully route the new belt around all the pulleys, saving a smooth, easily accessible pulley like the idler or water pump for last.
5. Final Step: Release the tensioner again and carefully slip the belt over the final pulley. Double-check that the belt is perfectly centered in the grooves of every ribbed pulley. An improperly seated belt can shred itself or get thrown off the pulleys once the engine starts. Slowly release the tool, allowing the tensioner to apply pressure.

Replacement Interval

Honda does not specify a strict mileage replacement interval for the serpentine belt. Instead, it falls under an "inspect, and replace if necessary" schedule during routine maintenance. As a general rule of thumb, most technicians recommend replacing the serpentine belt as a preventative measure every 60,000 to 90,000 miles. Belts are made of durable EPDM rubber, but they still degrade over time due to heat, friction, and environmental factors.

Signs of a Failing Belt or Tensioner

Your vehicle will give you warning signs before a belt fails completely. Ignoring them can lead to a breakdown, as the belt powers critical systems like the charging (alternator) and cooling (water pump) systems.

Signs of a Bad Belt:

• Squealing or Chirping Noises: This is the most common symptom, often worse on cold starts or in wet weather.
• Visible Wear: Look for cracks, glazing (shiny spots), fraying along the edges, or missing ribs.
• Accessory Malfunctions: If your battery light comes on (alternator not spinning) or the power steering feels heavy, the belt could be slipping or broken.

Signs of a Bad Tensioner:

• Grinding or Rumbling Noise: The bearing inside the tensioner pulley can fail, creating a constant noise that changes with engine RPM.
• Excessive Vibration: A weak tensioner spring will cause the tensioner arm to vibrate or jump erratically while the engine is running.
• Incorrect Belt Tracking: A failing tensioner can cause the belt to walk off the pulleys or wear unevenly on its edges.

If you are replacing a high-mileage belt, it is wise to replace the tensioner and idler pulley at the same time. These components have bearings that wear out and are subjected to the same heat and stress as the belt.

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