1218002 Valve Collet | Genuine Volvo Penta Part

🔧 Product Description

This is a genuine Volvo Penta valve collet from the Engine group, the small tapered locking half-collet that secures the valve spring retainer to the valve stem. It applies to the MD6, MD21 and AQD21 series marine diesel engines and is supplied as an individual piece, so quantities should be matched to the number of valves being serviced. It is the current replacement for the earlier collet part number and is a standard renewal item whenever the cylinder head valve train is dismantled.

🚤 Compatibility

• Year Range: Approximately mid-1970s-early 1990s

⚙️ Key Features

• OEM Volvo Penta part number 1218002
• System group: Engine
• Net weight 0.011 kg
• Supersedes previous part number 3848256
• Fits MD6, MD21 and AQD21 series marine diesel engines
• Sold as a single collet - order to suit the valve count being serviced
• Engine type: PRV 90-degree V6 petrol engine

🔌 Function

The valve collet locks the valve spring retainer onto the grooved end of the valve stem, holding the spring under compression so the valve returns fully to its seat. It transfers all valve spring load between the retainer and the stem throughout every opening and closing cycle.

⚠️ Common Signs of Failure

• Wear, flattening or rounding of the tapered mating faces so the collet no longer grips the stem groove
• Ticking or tapping noise from the valve train and inconsistent valve clearance
• Valve spring retainer sitting loose or the collet halves working out of position
• Visible cracks, chipping or fretting marks on the collet
• Loss of compression on one cylinder following a dropped valve

🛠️ Service Notes

• Supersedes earlier collet 3848256 - old paperwork may still reference that number, but this is the current stock item for MD6, MD21 and AQD21

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 1218002 → Supersedes 3848256 → Supersedes 818059

OEM / Related Numbers

• 3848256 earlier number superseded by this part
• 818060 earlier number superseded by this part
• 826786 earlier number superseded by this part
• 818059 earlier number superseded by this part
• Volvo B27 / B28 / B280 valve spring, retainer and valve-stem components

📦 Condition

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