Mercury – Quicksilver Lower Unit Drain and Fill Screw Seal | Gearcase Component | Nylon and Rubber Composite | 19183Q02

Overview

Keeping water out of your lower unit is one of the easiest — and most important — parts of drive maintenance. The Mercury Marine 19183Q02 Quicksilver Drain and Fill Screw Seals provide a tight, reliable seal every time you service your gear lube. Designed to fit 3/8-16 drain and fill screws found on MerCruiser sterndrives and most Mercury and Mariner outboards, these OEM gaskets ensure no leaks, no water intrusion, and no shortcuts when it comes to protecting your gears. Each pack includes four seals, giving you what you need for multiple services or spares.

Key Features

• Purpose: Creates a watertight seal for the drain and fill screws on your gearcase.
• Material: Made from durable nylon and rubber composite that compresses evenly for a leak-free fit.
• Fitment: Fits 3/8-16 drain/fill screws on MerCruiser drives and most Mercury/Mariner outboards.
• Compatibility: Works with all MerCruiser sterndrives and Mercury/Mariner outboards, excluding Verado and Japanese-built models.
• Quantity: Includes four OEM gaskets per pack.
• Performance: Prevents oil leaks and water contamination during routine gear lube service.

Engine & Boat Compatibility

• All MerCruiser sterndrives and most Mercury/Mariner outboards.
• Not compatible with Verado outboards or Japanese-origin engines.
• Commonly used across pontoons, cruisers, fishing boats, and performance hulls.
• Safe for freshwater and saltwater applications.

Performance & Practical Benefits

A worn or flattened gasket can let water into your gear lube or cause slow leaks. The 19183Q02 seal set prevents that, maintaining a clean, secure seal that keeps your drive protected. Each gasket is engineered to compress evenly without cracking, ensuring a snug fit every time you reinstall your drain or fill screws.

They’re small, inexpensive, and easy to replace — but they do a big job protecting the gears, bearings, and seals inside your drive. Swapping them out at every oil change or service keeps your lower unit dry, your gear lube clean, and your maintenance simple.

Why Buy OEM

Generic seals can be inconsistent in thickness or hardness, which can lead to leaks or uneven compression. The Quicksilver 19183Q02 is a genuine Mercury Marine part, built to the exact dimensions and material specifications Mercury drives require.

With OEM quality, you get dependable sealing performance that won’t degrade under pressure or exposure. It’s a small, inexpensive part that helps prevent major repair costs — the kind of smart maintenance Mercury owners trust.

FAQ

Q1: Which engines do these seals fit?
They fit all MerCruiser sterndrives and most Mercury/Mariner outboards, except Verado and Japanese-origin models.

Q2: How many gaskets come in a pack?
Each pack contains four OEM seals for multiple services.

Q3: Should I replace these at every oil change?
Yes — always replace the seals when servicing your lower unit to maintain a watertight seal.

Q4: What are they made from?
A nylon and rubber composite that’s flexible, durable, and resistant to marine fluids.

Q5: Are they suitable for saltwater use?
Absolutely. They’re designed to resist corrosion and maintain compression even after long exposure to salt and water.