Mercury MerCruiser Oil Pan Drain Plug Gasket | 8M0077608

Mercury MerCruiser Oil Pan Drain Plug Gasket | Part 8M0077608

Part Number: 8M0077608
Diagram Reference: Position 1116
Brand: Mercury Marine / Quicksilver
Official Product Type: Oil Pan Drain Plug Gasket
Category: Engine Gaskets & Seals

What It Does

This is the OEM drain plug gasket that seals the oil pan drain plug on applicable MerCruiser engines. It sits between the drain plug and the oil pan sealing surface to prevent oil from leaking past the plug after an oil change. The gasket compresses under torque to form a positive seal and must be replaced at every oil change — reusing a compressed or deformed gasket is one of the most common causes of oil leaks after service.

System

Engine lubrication system — oil pan drain plug sealing. The drain plug gasket is located at the lowest point of the oil pan, at the drain plug used to evacuate engine oil during oil changes. It is a single-use sealing component.

Compatible Applications

Verify fit using your engine model and serial number against the current Mercury parts diagram. Drain plug gasket specifications (diameter, material, thickness) can vary between engine families.

• MerCruiser sterndrive and inboard engines — confirm by model and serial number
• Mercury FourStroke outboard engines — confirm by model and serial number
• Use the Mercury parts diagram to confirm part 8M0077608 (diagram position 1116) is listed for your engine’s oil pan assembly

Serial Requirements

Drain plug gasket dimensions can vary between engine families and production ranges. Always confirm your engine model and serial number against the Mercury parts diagram before ordering. Do not assume this gasket fits all Mercury or MerCruiser engines — verify the diagram position and part number for your specific application.

Dimensions

Small-diameter crush gasket sized to the OEM drain plug for applicable engines. Exact outer diameter, inner diameter, and thickness are application-specific. Confirm against the Mercury parts diagram for your engine model. Do not substitute based on visual similarity — an incorrect gasket diameter or thickness will not seal properly.

Kit Contents

• 1 x Oil pan drain plug gasket

Drain plug not included. See related parts below if you also need the drain plug.

Related Parts

Commonly ordered together for a complete oil change service:

• Mercury Drain Plug – 5 Pack – Part 1199 — drain plug for applicable engines
• Mercury 4-Stroke Outboard Oil Drain Screw Washer – 12-803516
• Mercury MerCruiser Quicksilver Oil Filter 822626Q15
• Mercury MerCruiser Quicksilver Oil Filter 8M0116378
• Mercury MerCruiser Quicksilver Oil Filter 8M0123025
• Mercury MerCruiser Quicksilver Crankcase Oil Drain Pump Assembly 802889A1
• Mercury MerCruiser Quicksilver Oil Drain Pump Assembly 802889Q1
• Mercury MerCruiser OEM Oil Pan – 8M0150300

Service Interval

Replace at every oil change — this gasket is a single-use sealing component. Once compressed under torque, it will not re-seal reliably if reused. Mercury recommends engine oil changes every 100 hours or annually, whichever comes first. Always install a fresh drain plug gasket each time the drain plug is removed.

Installation Notes

• Always use a new gasket — never reuse the old one, even if it appears undamaged
• Clean the drain plug and oil pan sealing surface before installing the new gasket
• Hand-tighten the drain plug first to confirm it threads correctly, then torque to the specification in the Mercury service manual for your engine
• Do not overtighten — excessive torque crushes the gasket beyond its sealing range and can strip the oil pan threads
• Check for leaks after the first run following an oil change

Technical FAQ

Can I reuse the drain plug gasket?
No. This is a single-use crush gasket. Once compressed under torque, it will not return to its original shape and will not seal reliably if reused. Always install a new gasket at every oil change.

What happens if I skip the gasket?
Without the gasket, the drain plug relies on metal-to-metal contact with the oil pan, which will not seal reliably and will result in an oil leak. Always use the correct gasket.

How do I know if this is the right gasket for my engine?
Locate your engine model and serial number, then find part 8M0077608 (diagram position 1116) in the Mercury parts diagram for your engine’s oil pan assembly. If it appears there, this is the correct gasket.

My drain plug is leaking after an oil change — what should I check?
First confirm the gasket was replaced (not reused). Then check that the drain plug was torqued to the correct specification — both under-torque and over-torque can cause leaks. Also inspect the oil pan sealing surface and drain plug threads for damage.

Parts Desk Insights

Best use case: Routine engine oil service on MerCruiser sterndrive, inboard, and Mercury FourStroke outboard engines. This gasket should be ordered alongside the oil filter and fresh engine oil so the complete oil change can be done in one service visit without a return trip for a forgotten gasket.

Common issues:

• Gasket reuse — the most common cause of oil leaks after an oil change. The old gasket looks fine but has already been compressed and will not seal properly a second time. Always replace it.
• Wrong gasket ordered — drain plug gasket dimensions vary between engine families. Confirm the part number against the Mercury diagram for your specific engine before ordering.
• Overtightening the drain plug — crushing the gasket beyond its sealing range or stripping the oil pan threads. Torque to spec — do not use an impact wrench on the drain plug.
• Forgetting to order the gasket — a very common oversight when ordering oil change supplies. Add this to every oil change parts order for MerCruiser and Mercury FourStroke engines.