Serpentine Belt for MerCruiser V6 V8 Engine 8638763

Serpentine Belt for MerCruiser V6/V8 Engines – Fits Alpha & Bravo Models

This high-quality serpentine belt is designed for a wide range of MerCruiser V6 and V8 engines from 2001 to 2016. It is specifically compatible with Alpha engines equipped with a closed cooling system and Bravo engines with standard cooling.

This part is a direct replacement for MerCruiser OEM part numbers 57-865615-003 and 57-865615Q03, among others, ensuring a precise fit and reliable performance.

• Installation Type: Engine Accessory Drive
• Fuel Compatibility: Gasoline
• Included Component: One 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

This package includes:

• 1 x Serpentine Belt (Replaces 57-865615-003 / 57-865615Q03)

Installation Guide

1. Safety First: Ensure the engine is completely cool and the battery is disconnected before starting.
2. Locate the Belt: Identify the serpentine belt routing, noting the path it takes around the pulleys. Taking a photo can be helpful.
3. Release Tension: Use a wrench or belt tensioner tool on the automatic tensioner pulley to release the belt's tension.
4. Remove Old Belt: Carefully slide the old belt off the pulleys.
5. Inspect Pulleys: Before installing the new belt, check all pulleys for wobble, damage, or seizure. Spin them by hand to ensure they rotate smoothly.
6. Install New Belt: Route the new belt according to the diagram or the photo you took. Start with the crankshaft pulley and work your way around, leaving an easy-to-access pulley (like the alternator) for last.
7. Apply Tension: Release the tensioner tool to apply tension to the new belt. The tensioner should hold the belt firmly in place.
8. Final Check: Double-check that the belt is correctly seated in the grooves of every pulley.
9. Reconnect Battery: Reconnect the battery and start the engine to ensure the belt runs smoothly and quietly.

Troubleshooting & FAQ

How do I confirm this belt fits my engine?
Verify your engine model, year, and serial number against the compatibility chart. This belt is specifically for MerCruiser V6/V8 (2001–2016) Alpha engines with closed cooling and Bravo engines with standard cooling. Pay close attention to the serial number ranges noted in the table.

What are the common signs that my serpentine belt needs to be replaced?
Look for visible signs of wear such as cracking, fraying, glazing, or missing ribs. Squealing noises from the engine bay, especially on startup or when turning the wheel, are another common indicator. Failure of accessories like the alternator, power steering, or water pump can also result from a broken belt.

How often should I replace my serpentine belt?
It is recommended to inspect the belt during regular maintenance intervals (e.g., annually or every 100 hours). While there's no fixed replacement schedule, it should be replaced immediately if any signs of significant wear or damage are found, or as recommended by your engine's service manual.

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.