Lower Unit Components | Mercury Outboard

OEM and Cross Reference Numbers

Depending on manufacturer, catalog and aftermarket brand, this drain plug seal may be found under several different part numbers.

When replacing an existing seal, compare the original part number and verify the engine model or serial number before ordering.

What This Part is Used For

The 8M0082880 seal fits around the applicable lower-unit drain/fill screw. When the screw is tightened, the seal helps create a reliable barrier between the gearcase and the surrounding water.

A properly sealing drain screw is important because the lower unit needs to:

• Keep gear lubricant inside the gearcase
• Help prevent water from entering through the drain screw
• Maintain a reliable seal after routine gear-lube service

Mercury and Mariner Fitment

Mercury 8M0082880 appears in gearcase, driveshaft-housing and maintenance diagrams across a number of small Mercury outboard families. Applications shown in the supplied Mercury catalog information include the following.

Additional earlier Mercury applications are shown in the supplied catalog diagrams, including select carbureted 8, 9.9, 10, 15, 20 and 25 HP models and earlier 25/30 HP EFI applications. Because Mercury used multiple gearcase configurations within some horsepower families, verify the engine serial number and gearcase diagram when working with an earlier engine.

Johnson and Evinrude Fitment

Cross-reference data also identifies this seal for numerous Johnson and Evinrude 3-15 HP four-stroke model-number applications. Matching model families include:

The complete model suffix matters. When identifying this seal by Johnson or Evinrude model number, compare the complete engine model designation with the parts catalog rather than relying only on horsepower.

Nissan and Tohatsu Applications

Cross-reference information also shows this drain-plug seal across a broad range of older Nissan and Tohatsu outboard gearcase applications.

Supplied application data includes Nissan engines from approximately 2 HP through 140 HP across various 1996-2008 applications, including 2.5, 3.5, 4, 5, 6, 8, 9.8, 9.9, 15, 18, 20, 25, 30, 35, 40, 50, 60, 70, 90, 115, 120 and 140 HP listings.

The supplied data also specifically includes a 1996 Tohatsu 90 HP application.

Pro Marine Aftermarket Version Available

Pro Marine Drain Plug Seal - 9522P

Looking for an aftermarket alternative? Pro Marine also stocks the 9522P drain plug seal for customers who do not require the genuine Mercury-branded part.

This gives dealers, service shops and boat owners a choice between OEM Mercury 8M0082880 and the Pro Marine aftermarket 9522P.

View Pro Marine 9522P Drain Plug Seal

OEM Mercury or Pro Marine?

Replace the Seal When Servicing Gear Lube

Mercury recommends replacing the seal when changing gear lubricant or whenever the existing seal shows signs of wear or damage.

During lower-unit service:

1. Remove the applicable gearcase drain/fill screw.
2. Remove and inspect the existing seal.
3. Drain and refill the gearcase according to the engine manufacturer's procedure.
4. Install the correct drain-plug seal.
5. Reinstall and tighten the screw according to the manufacturer's specification.
6. Inspect the area for leakage after service.

Why the Lower Unit Drain Plug Seal Matters

Outboard gearcases operate submerged in water. The drain and fill screws therefore need reliable seals.

A damaged or incorrectly installed seal can compromise the sealing point around the screw. Water contamination can reduce the lubricating ability of the gear oil and may contribute to internal gearcase damage.

If drained gear lube appears unusually milky or shows other signs of water contamination, the gearcase should be inspected rather than simply refilled and returned to service.

Key Features and Benefits

• Genuine Mercury Marine OEM part
• Manufacturer item number 8M0082880
• Gearcase drain plug seal / washer
• Blue seal/washer
• Helps keep gear lubricant inside the lower unit
• Helps prevent water intrusion at the applicable drain screw
• Used on select Mercury and Mariner outboards
• Cross-references to select Johnson, Evinrude, Nissan and Tohatsu applications
• Multiple OEM and aftermarket cross-reference numbers
• Pro Marine 9522P aftermarket alternative available

FAQ

What is Mercury 8M0082880?
It is an OEM Mercury Marine gearcase drain plug seal / washer used on select outboard lower units.

What does the drain plug seal do?
It seals the applicable gearcase drain/fill screw to help keep gear lube inside the lower unit and water outside.

Should I replace the drain plug seal when changing gear lube?
Mercury recommends replacing the seal during gear-lube changes or when the existing seal shows signs of wear or damage.

Does 8M0082880 replace 95220?
Yes. 95220 is one of the listed cross-reference / superseded numbers associated with 8M0082880.

Does 8M0082880 replace 8M0075255?
Yes. 8M0075255 is listed as a cross reference for Mercury 8M0082880.

Does it cross to Sierra 18-60103?
Cross-reference data associates 18-60103 with this drain-plug seal application.

Does this fit Johnson and Evinrude outboards?
Cross-reference data includes numerous Johnson and Evinrude 3-15 HP four-stroke model-number applications. Verify the complete engine model number before ordering.

Does this fit Nissan and Tohatsu outboards?
Cross-reference data includes numerous Nissan and Tohatsu applications. Because the supplied application list spans multiple horsepower ranges, years and gearcase designs, verify the exact model and original part number before ordering.

Is there an aftermarket version?
Yes. Pro Marine stocks the 9522P Pro Marine Drain Plug Seal as an aftermarket alternative.

Is 8M0082880 OEM?
Yes. This listing is for the genuine Mercury Marine OEM version.

Searchable Part Numbers

8M0082880, 8M0075255, 8M0188617, 898101080, 95220, 95220010, 18-60103, 18-72656, 332600060, 332600060M, 332600061, 332600061M, 5040030, 9522P

Searchable Terms

Mercury drain plug seal, Mercury lower unit drain washer, Mercury gearcase drain seal, Mercury drain screw gasket, Mercury gear lube drain washer, Johnson drain plug seal, Evinrude drain plug seal, Tohatsu drain plug washer, Nissan outboard drain plug seal, lower unit drain screw seal, outboard gearcase washer

Compatible Applications

Yamaha OEM number 61A-45527-00-00 is used across a large range of Yamaha V4 and V6 outboards including Saltwater Series, EFI, OX66, HPDI, VMAX, and select four-stroke models. Mercury OEM 8886901 cross references to Mercury 225 and 250 EFI FourStroke applications.

OEM & Cross Reference Numbers

Available in Multiple Brands

OEM Yamaha 45527

Genuine Yamaha factory replacement for customers who prefer OEM parts.

View OEM Version

Pro Marine 45527P

Popular aftermarket replacement trusted by marine technicians and repair shops.

View Pro Marine Version

GLM 9076GM

Alternative aftermarket option from GLM Marine for the same Yamaha and Mercury applications.

View GLM Version

What This Part Is Used For

The driveshaft collar is part of the lower unit cooling system assembly and works with the water pump housing, wear plate, impeller, and related components. Proper spacing and alignment are critical to water pump performance and cooling system efficiency.

Many technicians replace collars whenever major water pump service is performed, particularly on high-hour engines or saltwater-operated boats.

Why Replace a Driveshaft Collar?

• Corrosion may affect proper component fitment
• Wear can impact water pump assembly alignment
• Often serviced during water pump rebuilds
• Helps maintain proper cooling system operation
• Ideal preventative maintenance item during lower unit service

Sierra 18-9076 Features

• Direct replacement for Yamaha 61A-45527-00-00
• Direct replacement for Mercury 8886901
• Fits many Yamaha V4 and V6 applications from 115HP-300HP
• Compatible with Mercury 225 and 250 EFI FourStroke models
• Quality Sierra Marine aftermarket construction
• OEM, Pro Marine, and GLM alternatives available above

FAQ

What OEM numbers does Sierra 18-9076 replace?
Yamaha 61A-45527-00-00 and Mercury 8886901.

What Yamaha engines commonly use this collar?
Many Yamaha 115HP, 130HP, 150HP, 175HP, 200HP, 225HP, 250HP, and 300HP V4 and V6 applications including OX66, VMAX, EFI, Saltwater Series, and select four-stroke models.

Does this fit Mercury outboards?
Yes. Mercury 225 and 250 EFI FourStroke models commonly use Mercury OEM 8886901.

Do you carry OEM and aftermarket alternatives?
Yes. OEM Yamaha, Pro Marine, and GLM versions are linked above.

Should I replace this during water pump service?
If wear, corrosion, or damage is present, replacement is recommended while the lower unit is apart.

Searchable Terms

Sierra 18-9076, 18-9076, Yamaha 61A-45527-00-00, Mercury 8886901, Yamaha V4 driveshaft collar, Yamaha V6 driveshaft collar, Yamaha VMAX water pump parts, Yamaha OX66 cooling system parts, Yamaha 225 driveshaft collar, Yamaha 250 driveshaft collar, Mercury 225 EFI FourStroke parts, Mercury 250 EFI FourStroke parts, Pro Marine 45527P, GLM 9076GM, OEM Yamaha 45527