Multi-Rib Belt for Volvo Penta D4, D6 260-370HP (2003+) (21407026)
Multi-Rib Belt for Volvo Penta D4, D6 260-370HP (2003+) (21407026) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Multi-Rib Belt for Volvo Penta D4, D6 260-370HP (2003+) (21407026)
Product Details
This aftermarket Multi-Rib Belt – Fits Volvo Penta D4, D6 260-370HP is designed for Volvo Penta D4 and D6 four-stroke diesel marine engines (2003 and newer) from 260 to 370 horsepower. It serves as a direct replacement serpentine/compressor belt for the engine driven belt system.
This belt is a direct interchange for Volvo Penta part numbers 21407026, 3583963, and 3584433.
- Manufactured to meet or exceed OEM specifications.
- Produced in an ISO 9002 certified facility to ensure quality.
- Includes a 1-year warranty against manufacturing defects under normal use.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Volvo Penta | 21407026 |
| Volvo Penta | 3583963 |
| Volvo Penta | 3584433 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Volvo Penta engines, verify your D4 or D6 model designation against the list to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Volvo Penta | D4-260A-A | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260A-B | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260A-C | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260A-D | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260A-E | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260A-F | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260D-B | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260D-C | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260D-D | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260D-E | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D4-260D-F | 260 | 4-Stroke | 2003+ | 21407026 |
| Volvo Penta | D6-350A-A | 350 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-350A-B | 350 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370A-B | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370A-C | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370A-D | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370A-E | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370D-B | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370D-C | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370D-D | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370D-E | 370 | 4-Stroke | 2004+ | 21407026 |
| Volvo Penta | D6-370D-F | 370 | 4-Stroke | 2004+ | 21407026 |
Technical Specs
- Product Type
- Multi-rib serpentine/compressor belt
- Installation
- Engine driven belt system
- Fuel Type
- Diesel
- Dimensions
- 1425mm (56⁷/₆₄ inches)
- Warranty
- 1-year against manufacturing defects (aftermarket)
- Other Technical Attributes
- Manufactured to OEM specifications, ISO9002 certified production
What’s in the Box
- 1 x Multi-Rib Belt (Replaces 21407026/3583963/3584433)
Installation Notes
- Ensure the engine is turned off and cooled completely.
- Disconnect the battery to prevent accidental starting.
- Loosen the alternator pivot bolt just enough to allow slight movement. Also loosen any adjuster-plate or tensioner bolts.
- Identify belt routing. Note the path around the crankshaft, water-pump, and alternator pulleys.
- Remove the old belt by swiveling the alternator or tensioner to relieve tension, then slip the belt off the pulleys.
- Inspect pulley grooves for wear, rust, or corrosion. Clean them to bare metal if needed.
- Route the new belt following the same pulley path. Ensure it seats properly in all V-grooves.
- Tension the belt: A correctly tensioned belt deflects about 1 cm (½″) under moderate thumb pressure on the longest span.
- Tighten all bolts: Secure the adjuster-plate bolt, then the main pivot bolt to factory torque specs.
- Reconnect the battery.
- Start the engine and observe belt tracking to ensure it is centered in the grooves and running smoothly.
- Shut down and recheck tension after a short run-in period, as new belts may stretch slightly.
Troubleshooting & FAQ
What is the difference between a "compressor" and "serpentine" belt?
For these Volvo Penta D4/D6 engines, the terms are often used interchangeably. This multi-rib belt drives the engine's accessories, which can include a supercharger (compressor). It functions as the main serpentine belt. Always confirm compatibility with your engine's specific part number.
How can I tell if my belt needs to be replaced?
Inspect your current belt for signs of wear such as cracks, splits, fraying, missing ribs, or a glazed, shiny appearance on the contact surfaces. Audible squealing or chirping from the engine bay is another common indicator that the belt is slipping and requires replacement.
What is the correct tension for this belt?
As a general guideline, the belt should have approximately 1 cm (½ inch) of deflection when pressed firmly with your thumb on the longest span between two pulleys. An over-tightened belt can cause premature failure of accessory bearings, while a loose belt can slip, squeal, and fail to operate accessories correctly.
Will this belt fit a D4-300 engine model?
This belt is specified for D4 models rated at 260HP and D6 models rated from 350-370HP. While it may fit other models, it is crucial to verify the required OEM part number for your specific D4-300 engine variant. If your engine specifies part number 21407026, 3583963, or 3584433, this belt is the correct fit.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It has been built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, it is batch-inspected for consistency and quality.
Shipping speed & cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free to most regions; expedited options appear at checkout where available.
Warranty & returns?
This product is covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
Payment & Security
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