26-66302 Mercury MerCruiser 8M0214939 Oil Seal | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver Upper Vertical Driveshaft Oil Seal - Part Number: 26-8M0214939

A genuine Quicksilver oil seal used in MerCruiser Alpha One Gen II upper unit vertical driveshaft sealing applications and selected Mercury / MerCruiser assemblies where the diagram specifies 26-66302 or current replacement 26-8M0214939. This seal helps retain gear oil and prevent water intrusion around the vertical driveshaft / carrier sealing area.

⚙️ Key Features

• Genuine Quicksilver OEM oil seal

• Correct current Mercury part number 26-8M0214939

• Supersedes earlier 26-66302 oil seal reference

• Used in MerCruiser Alpha One Gen II upper vertical driveshaft seal applications where specified

• Also listed for Mercury outboard and MerCruiser seal service locations matched by diagram

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 26-8M0214939 → Supersedes 26-66302

• 26-66302 earlier OEM oil seal reference

OEM / Related Numbers:

• 26-8M0214939

• 8M0214939

• 268M0214939

• 26-66302

• 66302

• Mercury 26-8M0214939

• Quicksilver 26-8M0214939

• Upper unit vertical driveshaft seal

• Carrier oil seal

• Crankcase oil seal reference where specified by Mercury diagram

• 25-21836 related O-ring family reference

Aftermarket / Verified Equivalents:

• Aftermarket oil seal equivalents exist where matched to 26-66302 / 26-8M0214939

• Typical replacement dimensions listed by aftermarket suppliers: 0.8750" shaft x 1.3750" outside diameter

🚤 Compatibility

Commonly used on:

• MerCruiser Alpha One Gen II upper unit vertical driveshaft sealing applications

• MerCruiser drive carrier oil seal service where 26-66302 / 26-8M0214939 is specified

• Mercury outboard and MerCruiser assemblies where this oil seal is shown in the serial-numbered diagram

Typically suits:

• Engine / drive models:

• MerCruiser Alpha One Gen II - serial 0D469859 to 0F679999 where upper vertical driveshaft seal 26-66302 is specified

• MerCruiser Alpha One Gen II - serial 0F680000 to 0K999999 where 26-66302 / 26-8M0214939 is specified

• MerCruiser Alpha One Gen II - serial 0L100040 and up where 26-8M0214939 is specified

• MerCruiser Alpha One Gen II upper gear housing service applications requiring the vertical driveshaft oil seal

• MerCruiser carrier oil seal service locations using the 26-66302 / 26-8M0214939 seal

• Mercury outboard assemblies where oil seal 26-8M0214939 is shown in the serial-numbered diagram

• Drive Type: MerCruiser Alpha One Gen II where specified

• Engine / Drive Type: Mercury / MerCruiser applications matched by serial-numbered diagram

• System Type: Upper vertical driveshaft oil seal / carrier oil seal

🔌 Function

The oil seal seals around the vertical driveshaft or carrier area to keep lubricant inside the drive and prevent water from entering the upper gear housing.

Common signs of failure:

• Gear oil leaking from upper seal area

• Water intrusion into drive oil

• Failed pressure or vacuum test

• Seal lip worn, hardened or torn

• Corrosion around seal bore

• Replacement required during upper gear housing or driveshaft service

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging