MerCruiser Serpentine Belt – Fits MerCruiser 5.0L/5.7L/6.2L/7.4L Alpha & Bravo
This serpentine belt is designed for Mercury MerCruiser V8 engines (5.0L, 5.7L, 6.2L, 7.4L, 350 MAG, 377 MAG, 383 MAG, 454 MAG, 502 MAG) from approximately 1998–2004. It is specifically for use on Alpha and Bravo stern drives and inboards equipped with power steering, closed cooling, and high mount alternator configurations.
This part is a direct replacement for Mercury part numbers 57-865615Q06, 865615006, 57-865615006, 57-8638766, and 57-8610491. It also replaces Sierra part number 18-15102.
- Constructed from high-strength rubber with embedded cords to resist shock load.
- Engineered to match OEM specifications for a reliable fit and performance.
- Installation is on the engine accessory drive.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
Brand |
Part Number |
Mercury |
57-865615Q06 |
Mercury |
865615006 |
Mercury |
57-865615006 |
Mercury |
57-8638766 |
Mercury |
57-8610491 |
Sierra |
18-15102 |
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.
Brand |
Model |
Stroke |
Years |
OEM Part No. |
Notes |
Mercury MerCruiser |
5.0L Alpha |
4-Stroke |
2000-2004 |
57-865615Q06 |
From Serial #OL619000 & OM600000+ |
Mercury MerCruiser |
5.0L Bravo |
4-Stroke |
2002-2004 |
57-865615Q06 |
From Serial #OM600000+ |
Mercury MerCruiser |
350 MAG Alpha |
4-Stroke |
2002-2004 |
57-865615Q06 |
From Serial #OM600000+ |
Mercury MerCruiser |
350 MAG Bravo |
4-Stroke |
2002-2004 |
57-865615Q06 |
From Serial #OM600000+ |
Mercury MerCruiser |
350 MAG MPI Alpha/Bravo EC |
4-Stroke |
[Data Needed] |
57-865615Q06 |
Serial #1A300000-1A611927 |
Mercury MerCruiser |
350 MAG MPI Alpha/Bravo EC |
4-Stroke |
[Data Needed] |
57-865615Q06 |
Serial #1A611928+ |
Mercury MerCruiser |
5.7L Alpha |
4-Stroke |
2000-2004 |
57-865615Q06 |
From Serial #OM600000+ |
Mercury MerCruiser |
5.7L Bravo |
4-Stroke |
2002-2004 |
57-865615Q06 |
From Serial #OM600000+ |
Mercury MerCruiser |
MX 6.2L MPI |
4-Stroke |
2002-2004 |
57-865615Q06 |
From Serial #OM600000+ |
Mercury MerCruiser |
MX 6.2L MPI Horizon |
4-Stroke |
2002-2004 |
57-865615Q06 |
From Serial #OM600000+ |
Mercury MerCruiser |
454 MAG MPI |
4-Stroke |
1998-2001 |
57-865615Q06 |
Serial #OL010029-OM024999, With 5¾" Pulley |
Mercury MerCruiser |
7.4L MPI |
4-Stroke |
1998-2001 |
57-865615Q06 |
Serial #OL010003-OM024330, With 5¾" Pulley |
Mercury MerCruiser |
502 MAG MPI |
4-Stroke |
1998-2001 |
57-865615Q06 |
Serial #OL017000-OM024999, With 5¾" Pulley |
Technical Specifications
Specification |
Value |
Product Type |
Serpentine Belt |
Installation |
Engine Accessory Drive |
Belt Length |
2,667 mm (105 inches) |
Belt Type |
High-strength rubber with multiple ribs |
Housing Material |
Rubber with embedded reinforcement cords |
Housing Color |
Black |
Weight |
0.53 lbs (0.24 kg) |
Warranty |
1 year Mercury Marine factory warranty |
Other Technical Attributes |
High-strength rubber cords resist shock load |
Package Contents
- 1 x Serpentine Belt (57-865615Q06)
Installation Guide
- Ensure the engine is off and has cooled down completely. Disconnect the battery for safety.
- Locate the belt routing diagram, which is often found on a decal in the engine compartment. If not present, take a picture or sketch the belt's path.
- Find the automatic belt tensioner. Use a serpentine belt tool or a long-handled wrench on the tensioner pulley bolt to release the tension.
- While holding the tensioner, carefully slide the old belt off one of the smooth pulleys.
- Once the old belt is loose, remove it from all pulleys.
- Compare the new belt with the old one to ensure the length and number of ribs match.
- Following your diagram, route the new belt around the grooved pulleys first, finishing with a smooth pulley that is easy to access.
- Release the tensioner again and guide the new belt into its final position.
- Double-check that the belt is centered on all pulleys and seated correctly in every groove.
- Reconnect the battery, start the engine, and watch the belt for a minute to confirm it is running smoothly and quietly.
Troubleshooting & FAQ
How do I know if this belt fits my MerCruiser engine?
This belt is designed for MerCruiser V8 engines (5.0L, 5.7L, 6.2L, 7.4L) from 1998–2004 with specific configurations like power steering and high-mount alternators. Please consult the "Compatible Engine Models" table and verify your engine's serial number to ensure an exact match.
What are the signs that my serpentine belt needs replacing?
Common signs include visible cracks, fraying, or glazing on the belt surface; squealing or chirping noises from the engine bay; or issues with accessories like the alternator or power steering pump failing to operate correctly.
How is this different from the original Mercury belt?
This is an aftermarket replacement built to meet or exceed original OEM specifications for fit and performance. It is made from high-strength rubber with reinforcement cords to resist shock load, ensuring reliability comparable to the original part.
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.
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Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.