3978589 Piston Pin | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta piston pin in the standard size, from the Engine group, weighing 0.814 kg and listed for 4 applications across the TWD and TD series. It supersedes part number 477900. Only 2 grams separate it from piston pin 3978588, so order by part number rather than by weight.

🚤 Compatibility

Typically suits:

• Volvo Penta TWD730ME
• Volvo Penta TWD731VE
• Volvo Penta TD730ME
• Volvo Penta TD730VE

• Engine Family: TWD, TD

⚙️ Key Features

• Standard size
• 0.814 kg
• Supersedes 477900
• 4 applications across the TWD and TD series

🔌 Function

Links the piston to the top of the connecting rod, carrying combustion load down into the rod while letting the rod swing.

⚠️ Common Signs of Failure

• Knocking or slapping from the top of the engine, loudest when cold
• Pin surface scored, blued or worn oval
• Free play felt between the pin and the small end
• Circlip grooves damaged or a clip found displaced
• Oil consumption rising alongside the knock

🛠️ Service Notes

• This is the standard-size listing — 3978588 is the neighbouring pin and the two cannot be told apart by weight
• Renew the circlips and check the small end bush at the same time

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 3978589 → Supersedes 477900 → Supersedes 477509

OEM / Related Numbers

• 477900 earlier number superseded by this part
• 477509 earlier number superseded by this part

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging