# 21424647 Belt Tensioner | Genuine Volvo Penta Part

🔧 Product Description

  

Genuine Volvo Penta D3 Automatic Accessory-Belt Tensioner - Part Number: 21424647

  

Genuine automatic belt tensioner for Volvo Penta D3 2.4-litre common-rail marine diesel engines. It maintains the correct load on the alternator and accessory-drive belt as the belt stretches and engine temperature changes.

  

⚙️ Key Features

  

• D3 automatic spring-loaded tensioner

• 2.4-litre five-cylinder marine diesel application

• Maintains accessory-belt tension

• Factory pulley alignment and spring rate

• D3 D- through H-generation application subject to serial confirmation

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• 21424647 - Current OEM part number

  

OEM / Related Numbers:

  

• 21424647

  

Aftermarket / Verified Equivalents:

  

• No aftermarket equivalent

  

🚤 Compatibility

  

Confirmed engine family:

  

• D3-110 through D3-220 marine diesel engines where tensioner 21424647 is specified

• D-, E-, F-, G- and H-generation D3 installations subject to belt-drive confirmation

  

• Confirm pulley, belt layout and engine serial number

  

🔌 Function

  

The tensioner keeps the accessory belt tight enough to drive the alternator and related components without slip.

  

Common signs of failure:

  

• Belt squeal or flutter

• Tensioner arm oscillation

• Weak spring force

• Pulley-bearing noise

• Belt tracking off-centre

• Repeated belt wear

  

📦 Condition

  

• Genuine Volvo Penta part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 354.68 AUD
- **Vendor:** Volvo Penta
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 354.68 AUD | In stock |

## Images

- 21424647 Belt Tensioner | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21424647-belt-tensioner-genuine-volvo-penta)
> Updated: 2026-08-03