19-865866 Mercury MerCruiser Seal | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver Bravo Shift Shaft Oil Seal Plug - Part Number: 19-865866

A genuine Quicksilver shift-cavity seal plug for selected Mercury MerCruiser Bravo sterndrive housings.

The formed plug fits into the designated shift-shaft oil passage in the revised Bravo housing design. It forms part of the drive sealing system, helping retain gear lubricant and prevent water entering through the shift-shaft cavity.

Mercury introduced this plug-style arrangement from Bravo drive serial number 0W258350, replacing the earlier O-ring-style sealing arrangement used in preceding housings.

⚙️ Key Features

• Genuine Quicksilver OEM shift-cavity seal plug

• Correct Mercury part number 19-865866

• Used in revised Bravo shift-shaft housing assemblies

• Plug-style design introduced from drive serial 0W258350

• Helps retain gear lubricant and prevent water intrusion

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 19-865866 current plug-style shift-cavity seal reference

• 25-62705 earlier O-ring sealing arrangement used before drive serial 0W258350

OEM / Related Numbers:

• 19-865866

• 865866

• 19865866

• 25-62705 earlier shift-cavity O-ring

• 62705

• 23-861209A1 related shift-shaft bushing kit

• 26-127091 related shift-shaft seal

• 806552A1 related shift yoke and cam assembly

• 745061655249

Aftermarket / Verified Equivalents:

• No aftermarket equivalent

🚤 Compatibility

Commonly used on:

• Mercury MerCruiser Bravo sterndrive shift-shaft cavities

• Revised plug-style Bravo driveshaft housing assemblies

• Standard, X-series and XR performance drives where the housing diagram specifies 19-865866

Typically suits:

• Drive models:

• MerCruiser Bravo One

• MerCruiser Bravo Two

• MerCruiser Bravo Three

• MerCruiser Bravo X One

• MerCruiser Bravo X Two

• MerCruiser Bravo X Three

• MerCruiser Bravo XR One

• MerCruiser Bravo XR Three

• MerCruiser Bravo XR SportMaster

• Mercury Racing Bravo XR Sport applications

• Integrated transom and high-performance Bravo assemblies using the revised shift-cavity plug

• Bravo One catalogue families beginning at serial 0W250000 where the later housing diagram specifies 19-865866

• Bravo Two catalogue families beginning at serial 0W250000 where the later housing diagram specifies 19-865866

• Bravo XR catalogue families beginning at serial 0W240000 where the later housing diagram specifies 19-865866

• Revised plug-style Bravo housing applications from serial 0W258350

• Drive Type: MerCruiser Bravo One, Bravo Two, Bravo Three, Bravo X and Bravo XR

• Serial Range: Revised seal-plug design introduced from 0W258350

• System Type: Shift-shaft cavity and driveshaft housing sealing system

• Year Range: Serial-number controlled; revised plug-style design introduced during 2006 production

🔌 Function

The seal plug closes the designated shift-shaft oil passage in the Bravo drive housing. It helps retain sterndrive gear lubricant, prevent water entry and maintain the housing's ability to pass pressure and vacuum testing.

Common signs of failure:

• Gear lubricant around the shift-shaft cavity

• Unexplained drop in drive-lubricant reservoir level

• Water-contaminated or milky gear lubricant

• Sterndrive fails pressure or vacuum testing

• Seal plug damaged, loose, deteriorated or missing

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging