V-Belt – Fits Volvo Penta TAMD/TMD 30, 31, 40, 41 Series Engines (Replaces 966978, 958359)

V-Belt – Fits Volvo Penta TAMD/TMD 30, 31, 40, 41 Series Engines (Replaces 966978, 958359)

This aftermarket alternator and raw water pump v-belt is designed for a wide range of Volvo Penta 4-stroke diesel inboard and sterndrive engines. It is compatible with models in the TAMD30, TMD30, TAMD31, TMD31, TAMD40, TMD40, and TAMD41 series, among others.

It serves as a direct replacement for Volvo Penta 966978 and 958359; Sierra 18-15435; OMC 912509; and Mercury 57-64416.

• Application: Drives the alternator and/or raw water pump.
• Construction: Built with high-strength synthetic cords to resist shock loads and ensure durability.
• Fuel Compatibility: Diesel

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.

Volvo Penta

OMC

MerCruiser

Technical Specifications

Package Contents

• 1 x V-Belt (966978/958359)

Installation Guide

1. Ensure the engine is turned off and has completely cooled. Disconnect the battery for safety.
2. Locate the belt tensioner, which is typically on the alternator or a separate idler pulley.
3. Use a wrench or socket to loosen the pivot bolt and adjustment bolt on the tensioner, allowing the component to move and release tension from the belt.
4. Carefully slide the old belt off all the pulleys.
5. Inspect the pulleys for any signs of damage, wobble, or residue. Clean them if necessary.
6. Route the new v-belt according to the engine's diagram, ensuring it is properly seated in the grooves of each pulley.
7. Apply tension to the belt by moving the alternator or tensioner back into position. The correct tension usually allows for about half an inch of flex when pressed firmly.
8. Tighten the adjustment and pivot bolts securely.
9. Reconnect the battery, start the engine, and listen for any unusual noises. Check that the belt is running true on the pulleys.

Troubleshooting & FAQ

How do I confirm this belt fits my Volvo Penta engine?
This belt replaces Volvo Penta parts 966978 and 958359. Please check the "Compatible Engine Models" table to verify your specific model, such as TAMD31A or AD40B, is listed. Cross-referencing the part number is the most reliable way to ensure a match.

What are the signs my v-belt needs replacing?
Common signs include visible cracks, deep splits, fraying edges, or a glazed, shiny appearance on the belt's sides from slipping. You might also hear a loud squealing noise from the engine bay, especially on startup or when the engine is under load.

How is this different from an OEM belt?
This is a high-quality aftermarket belt designed to meet or exceed OEM specifications for fit and performance. It is constructed with high-strength synthetic cords specifically to resist shock loads, providing durability 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.
• 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.