Volvo Penta D4/D6 Belt Idler Pulley – Fits D4-260, D4-300, D6-350, D6-370, D6-400 & D6-435
Volvo Penta D4/D6 Belt Idler Pulley – Fits D4-260, D4-300, D6-350, D6-370, D6-400 & D6-435 is backordered and will ship as soon as it is back in stock.
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Volvo Penta D4/D6 Belt Idler Pulley – Fits D4-260, D4-300, D6-350, ...
Volvo Penta D4/D6 Belt Idler Pulley – Fits D4-260, D4-300, D6-350, D6-370, D6-400 & D6-435 is backordered and will ship as soon as it is back in stock.
Product Details
This belt idler pulley is designed for specified Volvo Penta marine applications. It is used in the compressor belt system to guide the belt and support correct belt alignment and tension within the pulley assembly.
The company fitment information lists this pulley for Volvo Penta D4-260 and D4-300 engines up to serial number 2004017297, and D6-350, D6-370, D6-400 and D6-435 engines up to serial number 2006032252.
- Product type: belt idler pulley.
- Application: Volvo Penta compressor belt system.
- Single pulley supplied; this is not a kit.
- Confirm the engine model and serial-number limit before ordering.
Part Number References
The following Volvo Penta part numbers are listed as reference numbers for this pulley. Number references alone do not replace verification of the complete engine model and serial-number conditions.
| Brand | Part Number | Reference |
|---|---|---|
| Volvo Penta | 21280913 | Listed reference number |
| Volvo Penta | 3848896 | Listed reference number |
| Volvo Penta | 3809465 | Listed reference number |
| Volvo Penta | 3883786 | Listed reference number |
| Volvo Penta | 21172053 | Listed reference number |
Engine Compatibility
Match both the engine model and the serial-number limit shown below. Do not rely on the D4 or D6 family name alone.
| Brand | Engine Model | Rated HP | Serial-Number Condition | Reference Part No. |
|---|---|---|---|---|
| Volvo Penta | D4-260 | 260 | Up to serial number 2004017297 | 21280913 |
| Volvo Penta | D4-300 | 300 | Up to serial number 2004017297 | 21280913 |
| Volvo Penta | D6-350 | 350 | Up to serial number 2006032252 | 21280913 |
| Volvo Penta | D6-370 | 370 | Up to serial number 2006032252 | 21280913 |
| Volvo Penta | D6-400 | 400 | Up to serial number 2006032252 | 21280913 |
| Volvo Penta | D6-435 | 435 | Up to serial number 2006032252 | 21280913 |
Technical Specifications
- Product Type
- Belt idler pulley
- Application
- Volvo Penta compressor belt system
- Compatible Engine Family
- Specified Volvo Penta D4 and D6 applications
- Quantity
- 1 pulley
- Listed Reference Numbers
- 21280913, 3848896, 3809465, 3883786 and 21172053
What's in the Box
- 1 x Belt idler pulley
No additional belt, tensioner, mounting hardware or other components are identified in the company package information.
Installation Notes
Installation should be performed with the engine stopped and the vessel's electrical system isolated as appropriate for the service procedure. Use the engine manufacturer's service information for removal, belt routing, fastener torque and belt-tension specifications.
- Verify the engine model and serial number before beginning work.
- Locate the compressor belt system and identify the idler pulley.
- Release belt tension according to the applicable service procedure and remove the belt from the pulley.
- Remove the existing pulley while noting its orientation and mounting arrangement.
- Inspect and clean the mounting surface before installation.
- Install the replacement pulley and tighten the fastener to the manufacturer's specified torque.
- Route the belt correctly around all pulleys.
- Restore the specified belt tension and check pulley and belt alignment.
- Run the engine only after reassembly is complete, then inspect for abnormal noise, wobble or belt movement.
Troubleshooting & FAQ
How do I confirm whether this pulley fits my D4 or D6 engine?
Check the complete engine model and serial number. The listed D4 applications are D4-260 and D4-300 up to serial number 2004017297. The listed D6 applications are D6-350, D6-370, D6-400 and D6-435 up to serial number 2006032252.
What does this pulley do?
It is a belt idler pulley used in the compressor belt system. It guides the belt and supports proper belt alignment within the assembly.
What are common signs that an idler pulley needs attention?
Possible symptoms include unusual squealing or grinding, pulley wobble or play, rough rotation, belt tracking problems and accelerated or uneven belt wear. Inspect the complete belt system before replacing individual components.
Does this listing include a belt or tensioner?
No. The package contains one belt idler pulley. A belt, separate tensioner, mounting hardware and other components are not listed as included.
Can I use it on an engine with a higher serial number?
The listed fitment stops at the stated serial-number limits. If your engine serial number is higher, verify the correct part through the engine's service or parts information before ordering.
Is installation included?
Installation is not included. Follow the applicable Volvo Penta service procedure or have the work performed by a qualified marine technician.
Safety & Important Information
- Verify the engine model, serial number, existing pulley and belt routing before purchase and installation.
- Do not use the part-number list by itself to confirm fitment; the model and serial-number conditions must also match.
- Do not operate the engine with a damaged, misaligned or improperly tensioned belt.
- Professional installation is recommended where the correct belt procedure or torque specification is not available.
About Sea Sierra
- Marine Parts Support — We provide replacement components for marine service and maintenance applications.
- Fitment-Focused Listings — Product information is organized around engine models, serial-number conditions and reference numbers.
- Worldwide Fulfillment — Shipping options and delivery estimates are shown at checkout based on destination and availability.
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