Serpentine Belt – Fits MerCruiser 4.3L, 5.0L, 5.7L, 6.2L Sterndrive Engines (Replaces 57-865615Q04)

Serpentine Belt – Fits MerCruiser 4.3L, 5.0L, 5.7L, 6.2L Sterndrive Engines

This serpentine belt is designed for MerCruiser V6 4.3L and V8 5.0L, 5.7L, and 6.2L sterndrive engines from 2001 and newer (serial number 0M320025 and above) equipped with standard cooling systems. It is engineered to meet or exceed original equipment specifications, ensuring reliable power transmission to engine accessories like the alternator and sea water pump.

This part is a direct replacement for Mercury/MerCruiser part numbers 57-865615Q04, 865615004, 57-8638764, 57-862086A1, 57-8620861, and Sierra 18-15101. Please verify compatibility with your specific engine model and serial number before ordering.

• Direct replacement for easy installation with common tools.
• Built to match OEM specifications for reliable performance in standard cooling systems.
• Includes one (1) high-grade, fiber-reinforced serpentine belt.

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. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Serpentine Belt (57-865615Q04)

Installation Guide

1. Disconnect the boat's battery for safety.
2. Locate the serpentine belt and the belt tensioner. Take a photo or draw a diagram of the belt's routing for reference.
3. Use a breaker bar or serpentine belt tool to release the tension on the automatic tensioner pulley.
4. While holding the tensioner, carefully slide the old belt off the pulleys.
5. Inspect all pulleys for wear, damage, or seizure. Clean any debris from the pulley grooves.
6. Referring to your diagram, route the new belt around the pulleys, leaving the tensioner or an easily accessible smooth pulley for last.
7. Release the tensioner again and slide the belt fully onto the final pulley.
8. Double-check that the belt is correctly seated in all pulley grooves.
9. Slowly release the tensioner to apply pressure to the new belt.
10. Reconnect the battery and start the engine briefly to ensure the belt runs smoothly and quietly.

Troubleshooting & FAQ

How do I confirm this belt fits my MerCruiser engine?
Please check your engine's serial number. This belt fits V6 and V8 sterndrive models from 2001 and newer with a serial number of 0M320025 and above. It is only for engines with standard cooling systems, not closed or freshwater cooling. Refer to the 'Compatible Engine Models' table for your specific model.

What are the common signs that my serpentine belt needs replacement?
Common signs include visible cracks, fraying, or glazing on the belt surface; squealing or chirping noises from the engine bay, especially on startup; and overheating or a battery warning light, which can indicate the belt is slipping and not properly driving the alternator or water pump.

How often should I replace my engine's serpentine belt?
While there is no fixed interval, it's recommended to inspect the belt during every routine service. Most mechanics suggest replacement every 3-5 years or every 300-500 hours of operation, depending on usage and conditions, to prevent unexpected failure on the water.

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.