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Serpentine Belt – Fits MerCruiser Alpha/Bravo V6/V8 Engines (Replaces 57-865615-003, 57-865615Q03)
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Serpentine Belt – Fits MerCruiser Alpha/Bravo V6/V8 Engines (Replaces 57-865615-003, 57-865615Q03)
This serpentine belt is designed for Mercury Marine/MerCruiser 4.3L, 5.0L, 5.7L, and 6.2L V6/V8 engines (1999–2016). It is specifically compatible with Bravo and Alpha models equipped with sea pump cooling systems.
This component is a direct replacement for multiple OEM and aftermarket part numbers, ensuring a precise fit and function for specified engine configurations.
- Engine Accessory Drive Belt
- Constructed from high-strength rubber cords for durability
- Fits Alpha drives with closed cooling and Bravo drives with standard cooling
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury / MerCruiser | 57-865615-003, 57-865615Q03 |
| Quicksilver | 865615Q03 |
| Sierra | 18-15100 |
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 | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 4.3L | V6 | 4-Stroke | 1999-2016 | 57-865615-003, 57-865615Q03 | Bravo engine or Alpha with sea pump |
| MerCruiser | 5.0L | V8 | 4-Stroke | 1999-2016 | 57-865615-003, 57-865615Q03 | Bravo engine or Alpha with sea pump |
| MerCruiser | 5.7L | V8 | 4-Stroke | 1999-2016 | 57-865615-003, 57-865615Q03 | Bravo engine or Alpha with sea pump |
| MerCruiser | 6.2L | V8 | 4-Stroke | 1999-2016 | 57-865615-003, 57-865615Q03 | Bravo engine or Alpha with sea pump |
| MerCruiser | Alpha | V6/V8 | 4-Stroke | 2001-2016 | 57-865615-003, 57-865615Q03 | With closed cooling |
| MerCruiser | Bravo | V6/V8 | 4-Stroke | 2001-2016 | 57-865615-003, 57-865615Q03 | With standard cooling (s/n 0M320025 and above) |
| MerCruiser | 305 CID | V8 | 4-Stroke | 2001-2016 | 57-865615-003, 57-865615Q03 | Alpha with closed cooling or Bravo with standard cooling |
| MerCruiser | 350 CID | V8 | 4-Stroke | 2001-2016 | 57-865615-003, 57-865615Q03 | Alpha with closed cooling or Bravo with standard cooling |
| MerCruiser | 377 CID | V8 | 4-Stroke | 2001-2016 | 57-865615-003, 57-865615Q03 | Alpha with closed cooling or Bravo with standard cooling |
Technical Specifications
| Specification | Value |
|---|---|
| Product Type | Serpentine Belt |
| Installation | Engine Accessory Drive |
| Material | High Strength Rubber Cords |
| Belt Length | 2,704 mm (106.5 in) |
| Belt Type | Serpentine/Multi-Rib |
| Compatibility | Alpha with Sea Pump, Bravo Standard Cooling |
| Color | Black |
| Warranty | 1-year factory warranty against defects (Mercury/Quicksilver) |
| OEM Part Number | 57-865615-003, 57-865615Q03 |
Package Contents
- 1 x Serpentine Belt (57-865615-003, 57-865615Q03)
Installation Guide
- Safety First: Disconnect the boat's battery before beginning any work on the engine.
- Locate Components: Identify the serpentine belt, tensioner pulley, and the belt routing diagram (often on a decal on the engine).
- Release Tension: Use a wrench or socket on the tensioner pulley to release the belt's tension.
- Remove Old Belt: Carefully slide the old belt off the pulleys.
- Route New Belt: Following the routing diagram precisely, thread the new belt around the pulleys.
- Apply Tension: Slowly release the tensioner to apply pressure to the new belt.
- Final Check: Ensure the belt is properly seated in the grooves of all pulleys. Reconnect the battery and test the engine.
Troubleshooting & FAQ
How do I confirm this belt fits my engine?
Verify your engine model and year in the compatibility table above. The most critical factors are your drive type (Alpha or Bravo) and the specific cooling system (sea pump, standard cooling, or closed cooling). This belt fits very specific configurations.
What are the signs of a failing serpentine belt?
Common signs include a persistent high-pitched squealing sound from the engine, visible cracks or fraying on the belt's surface, and issues with engine accessories like the alternator or power steering pump.
How often should I replace my serpentine belt?
We recommend annual inspection for wear, cracks, or glazing. For replacement intervals, consult your engine's service manual, but a general guideline is to replace it every 300-500 operating hours or if any signs of wear are visible.
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.
We can ship to virtually any address in the world with free shipping available for most regions.
For our typical US and Canadian customers , our shipping timeframes are as follows:
- Amazon FBA: orders will be delivered within 1-5 business days after placing the order (during certain special periods such as major promotions, Christmas, etc., the delivery time of Amazon FBA may be affected).
- US warehouse shipment: orders will be delivered within 5 days after placing the order.
- China warehouse shipment: orders will be delivered about 12 days after placing the order.
When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.
Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.
Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.
As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.
We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.
Parts Finder
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Our database is currently being updated and expanded. More models, including Yamaha, Mercury, and Suzuki, are being verified and uploaded.
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