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