Serpentine Drive Belt – Fits Volvo Penta D4 & D6 Marine Engines

Serpentine Drive Belt – Fits Volvo Penta D4 & D6 Marine Engines

This aftermarket serpentine drive belt is designed for reliable performance in Volvo Penta D4 and D6 series diesel marine engines. It is engineered to meet or exceed OEM specifications for fit, form, and function, providing power to critical engine accessories like the water pump and alternator.

This belt is a direct replacement for Volvo Penta part numbers 21405493, 23324914, and 3817787, as well as other aftermarket equivalents.

• Installation Location: Engine External
• Compatible Fuel Type: Diesel
• Material: Constructed from durable rubber with polyester reinforcement for longevity.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 x Serpentine Drive Belt (Replaces OEM 21405493, 23324914, 3817787)

Installation Guide

1. Safety First: Ensure the engine is off and cool, and disconnect the battery terminals.
2. Locate Components: Identify the serpentine belt, tensioner pulley, and all accessory pulleys. Take a picture or note the belt's routing path if a diagram is not available.
3. Release Tension: Use a suitable wrench or breaker bar on the automatic tensioner to release the pressure on the belt.
4. Remove Old Belt: While holding the tensioner, carefully slip the old belt off the pulleys.
5. Inspect Pulleys: Before installing the new belt, spin each pulley by hand to check for wobble, noise, or resistance, which could indicate a failing component.
6. Route New Belt: Following your diagram or photo, route the new belt around the pulleys, leaving a smooth pulley (like the water pump) for last.
7. Apply Tension: Slowly release the tensioner, ensuring the belt seats correctly into all pulley grooves. Double-check the alignment.
8. Final Check: Reconnect the battery, start the engine, and listen for any unusual noises. Visually confirm the belt is running true on all pulleys.

Troubleshooting & FAQ

How do I confirm this belt fits my engine?
This belt is designed for all horsepower variants of the Volvo Penta D4 and D6 diesel marine engines. The best way to verify fit is to check your current belt or engine's service manual for part numbers 21405493, 23324914, or 3817787. You can also use our compatible models table above for reference.

What are common signs that a serpentine belt needs replacement?
Look for visible signs of wear such as cracks, glazing (shiny surface), fraying, or missing ribs. Audible signs include persistent squealing or chirping noises from the engine, especially on startup or when accelerating. A failing belt can also cause poor performance of the alternator or water pump, leading to charging or cooling issues.

How often should I replace my serpentine belt?
We recommend inspecting the belt during every routine engine service. Replacement intervals depend on engine hours and operating conditions. Follow the preventative maintenance schedule in your Volvo Penta owner's manual or replace the belt immediately if you notice any signs of wear or damage.

OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.