# 21255742 Main Bearing | Genuine Volvo Penta Part

🔧 Product Description

  

Genuine Volvo Penta Main Bearing - Part Number: 21255742

  

Genuine crankshaft main bearing used in Volvo Penta MD-series compact marine diesel engines.

  

⚙️ Key Features

  

• Genuine Volvo Penta crankshaft bearing

• Precision bearing surface

• Maintains correct crankshaft oil clearance

• Suitable for engine overhaul

• Must be matched to the measured crankshaft journal size

  

🔄 Supersession & Cross Reference

  

OEM Supersession Chain:

  

• Current or final OEM reference: 21255742

• The part is no longer supplied in some markets

  

OEM / Related Numbers:

  

• 21255742

  

Aftermarket / Verified Equivalents:

  

• No aftermarket equivalent

  

🚤 Compatibility

  

Confirmed application:

  

• MD2030-D cylinder block and flywheel-housing assembly

  

Related MD-series use must be confirmed by crankshaft size and engine serial number.

  

🔌 Function

  

The bearing supports the crankshaft and maintains the lubricating-oil film needed to prevent metal-to-metal contact.

  

Common signs of failure:

  

• Low oil pressure

• Crankshaft knock

• Excessive journal clearance

• Metallic debris in the oil

• Scoring or heat discolouration

• Bearing material worn through to the backing

  

📦 Condition

  

• Genuine Volvo Penta part

• Brand new

• Supplied in original or equivalent packaging

## Details

- **Price:** 184.57 AUD
- **Vendor:** Volvo Penta
- **Tags:** Volvo Penta

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 184.57 AUD | In stock |

## Images

- 21255742 Main Bearing | Genuine Volvo Penta Part

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> Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/products/21255742-main-bearing-genuine-volvo-penta)
> Updated: 2026-08-02