MerCruiser Serpentine Belt 57-865615Q03 - Fits V6/V8 Alpha & Bravo Engines

MerCruiser Serpentine Belt 57-865615Q03 – Fits V6/V8 Alpha & Bravo Engines (Replaces 57-865615-003)

This serpentine belt is designed for MerCruiser V6 & V8 (305, 350 & 377 cid) engines from 2001–2016. It specifically fits Alpha drive engines equipped with a closed cooling system and Bravo drive engines with a standard cooling system. Please verify your engine serial number falls within the range of 0M320025 through 2A455872 to ensure compatibility.

This part is a direct replacement for MerCruiser part numbers: 57-865615-003, 57-865615Q03, 57-8638763, 57-862807, and 57-862087A1.

• Direct Fit: Installs as a direct OEM-specification replacement without modification.
• Durable Construction: Made from reinforced, OEM-specification rubber designed to withstand the harsh marine environment.
• Application: Drives the sea water pump and other engine accessories.

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 (57-865615Q03)

Installation Guide

Professional installation is recommended. The general steps for replacement are as follows:

1. Safety First: Disconnect the engine's battery before beginning work.
2. Diagram the Belt Path: Before removal, take a clear photo or draw a diagram of how the current belt is routed around the pulleys.
3. Release Tension: Locate the automatic belt tensioner. Use a socket wrench or a designated belt tensioner tool to rotate the tensioner and release the pressure on the belt.
4. Remove the Old Belt: Carefully slide the old belt off the pulleys.
5. Inspect Components: Check all pulleys for wobble, damage, or signs of excessive wear. Clean any debris from the pulley grooves.
6. Install the New Belt: Route the new belt according to your diagram, starting with the crankshaft pulley and finishing with an easy-to-access smooth pulley.
7. Verify Alignment: Double-check that the belt is properly seated in the grooves of every pulley.
8. Apply Tension: Slowly release the tensioner to apply pressure to the new belt. Remove your tool.
9. Final Check: Reconnect the battery, start the engine, and listen for any unusual noises. Ensure the belt is running smoothly.

Troubleshooting & FAQ

How do I confirm this belt fits my engine?
Verify your engine is a MerCruiser V6 or V8 model made between 2001-2016. Most importantly, check that your engine's serial number is between 0M320025 and 2A455872. Also, confirm your cooling system matches: this belt is for Alpha drives with closed cooling or Bravo drives with standard cooling.

What are the signs that my current serpentine belt needs replacing?
Common symptoms of a failing belt include loud squealing or chirping sounds from the engine bay, visible cracks, frays, or glazing on the belt's surface, and intermittent or complete failure of accessories like the power steering pump or alternator.

How often should I replace my serpentine belt?
While there is no fixed interval, it is best practice to inspect the belt during regular engine maintenance. We recommend following the replacement schedule provided in your MerCruiser service manual. Belts typically last for several hundred hours of use but can degrade faster in harsh marine conditions.

Is a special tool required for installation?
In most cases, you will only need a standard socket wrench or breaker bar that fits the bolt head or square hole on the automatic belt tensioner to release the tension. No other special tools are typically required.

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.