8M0089639 Mercury MerCruiser L/U Gasket Set | Genuine Quicksilver OEM Part

🔧 Product Description

Genuine Quicksilver Lower-Unit Gasket Set - Part Number: 27-8M0089639

A genuine Quicksilver lower-unit gasket and seal set for selected Mercury and Mariner 25HP and 30HP two-cylinder outboards and 25 Jet gear housings.

The set contains the principal gaskets and sealing components required when dismantling and rebuilding the applicable lower unit. It is intended for gearcase repairs where disturbed seals and gaskets must be renewed before pressure testing and refilling with lubricant.

⚙️ Key Features

• Genuine Quicksilver OEM lower-unit gasket set

• Correct Mercury part number 27-8M0089639

• Supersedes earlier gasket set 27-95220A1

• Used on selected 25HP, 25 Jet and 30HP two-cylinder lower units

• Suitable for complete gearcase teardown and resealing

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 27-8M0089639 → Supersedes 27-95220A1

• 27-95220A1 earlier OEM lower-unit gasket-set reference

OEM / Related Numbers:

• 27-8M0089639

• 8M0089639

• 278M0089639

• 27-95220A1

• 95220A1

• 745061606258

Aftermarket / Verified Equivalents:

• SeaSierra: Lower-Unit Gasket and Seal Kit replacing 27-8M0089639 / 27-95220A1

• Replacement kit references: 8M0089636

• Replacement kit references: 27-804908A01

🚤 Compatibility

Commonly used on:

• Mercury and Mariner 25HP and 30HP two-cylinder lower units

• Mercury 25 Jet pump and gear-housing assemblies

• Lower-unit resealing during bearing, shaft or gear service

Typically suits:

• Engine models:

• Mercury / Mariner 25HP 2-cylinder international - serial 0N018456 to 0N055504

• Mercury / Mariner 25HP and 30HP two-stroke international - serial 0N055505 and above

• Mercury 25 Jet - serial 0N088578 and above

• Mercury / Mariner 30HP 2-cylinder international - serial 0N001875 to 0N055504

• Mercury / Mariner 30HP 2-cylinder international later-production gearcases

• Mercury / Mariner 25HP and 30HP lower units using original gasket set 27-95220A1

• HP Range: 25HP - 30HP

• Engine Type: Mercury / Mariner two-cylinder two-stroke and Jet outboard

• Year Range: Approximately late 1990s through the 2000s, dependent on serial number

🔌 Function

The gasket set restores the seals between the lower-unit housings, shafts and service covers after disassembly. Correct installation allows the gearcase to retain lubricant and pass its required pressure and vacuum tests.

Common signs of failure:

• Gear lubricant leaking from a lower-unit joint

• Milky or water-contaminated gear oil

• Gearcase fails pressure or vacuum testing

• Gaskets torn or compressed during disassembly

• Lower-unit rebuild requires all disturbed seals to be renewed

📦 Condition

• Genuine Quicksilver part

• Brand new

• Supplied in original or equivalent packaging