Serpentine Belt – Fits MerCruiser 4.3/5.0/5.7/6.2L V6/V8 Engines (Replaces 57-861757Q, 57-861757)

Serpentine Belt – Fits MerCruiser 4.3/5.0/5.7/6.2L V6/V8 Engines (Replaces 57-861757Q, 57-861757)

This replacement serpentine belt is designed for MerCruiser V6 and V8 engines, specifically 4.3L, 5.0L, 5.7L, and 6.2L models from approximately 1996–1999 that are equipped with standard cooling and a 5 3/4 inch pulley. It is engineered to meet or exceed OEM specifications for reliable performance.

This part is a direct replacement for Mercury/MerCruiser part numbers 57-861757Q and 57-861757, as well as Sierra part number 18-15115.

• Constructed from durable rubber with reinforced fibers for longevity and grip.
• Engineered to the specific length of 97.5 inches (2471 mm) required for these applications.
• Package includes one (1) high-quality replacement 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

• 1 × Serpentine Belt (Replaces 57-861757Q, 57-861757)

Installation Guide

1. Safety First: Ensure the engine is off and cool, and disconnect the battery terminals.
2. Locate Tensioner: Identify the automatic belt tensioner pulley.
3. Release Tension: Use a properly sized wrench or breaker bar on the tensioner to rotate it and release tension from the belt.
4. Remove Old Belt: While holding the tensioner, carefully slide the old belt off the pulleys. Note the routing path before removal.
5. Install New Belt: Route the new belt around the pulleys according to your engine's diagram. Ensure all ribs are correctly seated in the pulley grooves.
6. Apply Tension: Slowly release the tensioner, allowing it to apply the correct tension to the new belt.
7. Final Check: Double-check that the belt is properly aligned and seated on every pulley.
8. Test: Reconnect the battery, start the engine, and listen for any unusual noises. Let it run for a minute to ensure proper operation.

Troubleshooting & FAQ

How do I confirm this belt fits my engine?
This belt fits MerCruiser V6 (4.3L) and V8 (5.0L, 5.7L, 6.2L) sterndrive engines from approximately 1996-1999, specifically those using a 5 3/4 inch pulley and a standard cooling system. The most reliable method is to match the part number (57-861757Q or 57-861757) from your old belt or service manual. Please verify these details before ordering.

What are common signs of a failing serpentine belt?
Look for symptoms such as loud squealing or chirping noises from the engine, visible cracks, glazing, or fraying on the belt's surface. A failing belt can also cause issues with the alternator charging, power steering assist, or engine cooling.

How often should a serpentine belt be replaced?
It is best practice to inspect the belt during regular maintenance intervals (e.g., every oil change). While there's no universal replacement timeline, most mechanics recommend replacement every 60,000 to 100,000 miles or immediately if signs of wear or damage are present.

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.