Mercury – Trim Cylinder O-Ring Kit | Hydraulic Trim System | Rubber Seals | 87400A2

Overview

If you’ve spent enough hours on the water, you can feel when your trim system stops behaving the way it should. The stern doesn’t lift as cleanly, the bow angle feels off, or you start seeing a bit of hydraulic film where it doesn’t belong. That’s usually your trim cylinder telling you it needs some attention. The Quicksilver 87400A2 O-Ring Kit is one of those small, unassuming fixes that can completely restore the feel of your boat. There’s a real confidence that comes from bringing a tired trim system back to life — that smooth rise, that quiet, steady movement, the sense that your boat is responding exactly the way you expect. It’s a simple kit, but it delivers a big dose of trust in your gear again.

Key Features

• Complete 11-piece kit designed for MerCruiser trim cylinders
• Durable rubber seals engineered specifically for hydraulic marine use
• Replaces worn or leaking o-rings to restore full trim function
• Built to Mercury Marine OEM standards for perfect fit and lasting performance
• Includes all sealing components required for a full trim cylinder reseal

Engine & Boat Compatibility

• Fits MerCruiser R, MR, Alpha One, Alpha One Gen II, and Bravo trim cylinders
• Works with both sterndrive and inboard/outboard applications
• Suitable for a wide range of boat types, including center consoles, cruisers, bowriders, pontoons, and freshwater fishing boats

Performance & Practical Benefits

A boat’s trim system is something you feel more than you think about. When the seals begin to fail, the signs show up slowly at first — a little hesitation, a slight delay, a drift in hydraulic pressure. Replacing the o-rings with this Quicksilver kit brings that crisp, predictable motion back. Your engine raises and lowers smoothly, the cylinders stay dry, and the whole system feels tighter and more controlled.

Each seal in the kit is engineered to handle hydraulic pressure, constant temperature changes, and the moisture-rich environment of marine operation. You’ll notice how much steadier your engine holds its position when the trim is engaged. There’s a satisfying “set” when you find the sweet spot on plane, and the cylinders operate quietly without weeping fluid or leaving residue along the rams.

It’s also a practical upgrade — one of the most cost-effective ways to extend the life of your trim cylinders and avoid expensive replacements. Because the parts are OEM-spec, everything seats naturally and installs without the frustration that often comes with off-brand seal kits. No odd tolerances, no mismatched thicknesses… just components that fit the way they’re supposed to.

Why Buy OEM

Trim systems are unforgiving when it comes to cheap sealing components. Aftermarket o-rings might look similar, but they rarely carry the same resilience under pressure or exposure to marine fluids. With OEM Quicksilver parts, you get seals that are molded, sized, and tested specifically for MerCruiser cylinders. That means longer service intervals, fewer leaks, and a trim system that performs the way the designers intended. For any boater who’d rather fix it once and fix it right, OEM is the clear call.

FAQ

Q1: Which Mercury engines or systems does this kit fit?

It fits MerCruiser R, MR, Alpha One, Alpha One Gen II, and Bravo trim cylinders.

Q2: What makes it better than aftermarket kits?

OEM materials, correct sizing, and seals designed specifically for marine hydraulic loads.

Q3: How do I confirm this is the right kit for my cylinders?

Match your system to Mercury Marine part number 87400A2 or check your trim cylinder’s parts diagram.

Q4: Can these seals be used in both freshwater and saltwater?

Absolutely — they’re designed for full marine exposure.

Q5: Is installation easy?

If you’ve rebuilt hydraulic components before, it’s straightforward. Most boaters can handle it with basic tools and a clean workspace.