Serpentine Belt – Fits Mercury Verado 135-400HP Engines (Replaces 57-880566Q14, 880566Q14, 8M0232583)

Serpentine Belt – Fits Mercury Verado 135-400HP Engines

This serpentine belt is designed for a wide range of Mercury Verado engines. It ensures reliable power transmission to critical engine components, including the supercharger, alternator, and water pump. It is engineered to fit 135-200HP 4-Cylinder Verado models (2004–present), 200-300HP 6-Cylinder Verado models (including Gen V), and 350-400HP 6-Cylinder Verado models.

This is a direct-fit replacement for Mercury part numbers 57-880566Q14, 880566Q14, and 8M0232583, as well as Sierra part number 18-15128. Always verify your engine's serial number and existing part number before ordering.

• Engineered as an engine-specific replacement for a precise fit.
• Drives the engine supercharger and essential accessories.
• Meets or exceeds OEM specifications for durability and performance.

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 (Replaces 57-880566Q14/880566Q14/8M0232583)

Installation Guide

1. Ensure the engine is turned off and completely cooled before beginning.
2. Disconnect the battery to prevent any accidental starting.
3. Loosen the alternator pivot bolt just enough to allow movement. Loosen any adjuster-plate or tensioner bolts as well.
4. Identify the existing belt routing. Take note of the path around the crankshaft, water pump, and alternator pulleys.
5. Remove the old belt by swiveling the alternator or tensioner to relieve tension, then carefully slip the belt off all pulleys.
6. Inspect all pulley grooves for signs of wear, rust, or corrosion. Clean them thoroughly if necessary.
7. Route the new belt following the same pulley path, ensuring it seats correctly in all grooves.
8. Tension the new belt by swiveling the alternator away from the engine. A correctly tensioned belt should deflect about 1 cm (½") under moderate thumb pressure on its longest span.
9. Tighten all bolts securely. Secure the adjuster-plate bolt first, then tighten the main pivot bolt to factory torque specs.
10. Reconnect the battery.
11. Start the engine and observe the belt tracking to ensure it is centered in the grooves and running smoothly.
12. Shut down the engine and recheck the belt tension after a short run-in period, as new belts may stretch slightly. Re-tension if necessary.

Troubleshooting & FAQ

How do I confirm this belt fits my Mercury Verado engine?
Check your engine's serial number. This belt fits 4-Cylinder Verado models with SN 1B311420 & above, 6-Cylinder models with SN 1B390143-2B144127 (pre-Gen V) and 2B144123 & above (Gen V), and 350-400HP models with SN 2B141617 & above. You can also cross-reference your existing part number with 57-880566Q14, 880566Q14, 8M0232583, or Sierra 18-15128.

How often should I replace the serpentine belt?
The recommended replacement interval is every 300 hours of standard operation. For high-demand applications, such as the Mercury Racing 400R, a more frequent interval of 100 hours is recommended to ensure reliability.

What are the signs of a failing serpentine belt?
Common signs include visible cracking, glazing, or fraying on the belt's surface. You might also hear a squealing or chirping noise from the engine bay, especially during startup or when accelerating. A failing belt can also lead to issues with the battery charging system (alternator) or engine overheating (water pump).

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.