Mercury – Trim and Tilt Cylinder End Cap | Hydraulic System Component | Aluminum Alloy | 8M0021648

Overview

Any boater who spends enough time on the water knows how much you rely on your trim and tilt system. It is one of those things you barely think about when it is working right, but you feel it immediately when something is off. A smooth trim lets you settle the bow exactly where you want it—lifting over chop, easing into shallow water, or finding that perfect running angle on a long stretch of open water. Mercury Marine part 8M0021648 brings back that confidence. It is a small but essential end cap that keeps the entire hydraulic system sealed, steady, and responsive. When you know your equipment is working the way it should, the whole day on the water just feels easier.

Key Features

• Genuine Mercury Marine hydraulic trim and tilt cylinder end cap
• Designed for select 110–300 horsepower Mercury and Mariner outboards
• Durable aluminum alloy construction for strength and corrosion resistance
• Precision-machined for a tight, secure hydraulic seal
• Built to factory specifications for proper trim system pressure and response
• Easy installation with common shop tools

Engine & Boat Compatibility

• Fits select 110–300 horsepower Mercury and Mariner outboards across multiple lines:
  • Two-stroke EFI
  • Sport XS and Pro XS
  • DFI and DTS
  • Marathon, SeaPro, and ProMax
  • JP, XB, XR6, Magnum III
  • 2.5L and 3.0L platforms
  • Select Verado models
• Common on bass boats, bay boats, offshore center consoles, flats skiffs, pontoons, and runabouts
• Ideal for boats frequently trimmed during rough-water running, shallow entries, and trailering

Performance & Practical Benefits

When a trim system starts to weaken, you feel it long before you see it. The bow stops responding as cleanly. The engine might hesitate when raising. Sometimes you hear a faint change in pump tone. This end cap helps return that smooth, confident movement you expect from a properly tuned Mercury hydraulic setup.

Once installed, the system feels tight again—no sponginess, no drift, no slow settling. The engine lifts and drops with the steady pace you remember from the first season you owned it. The cap’s durable aluminum alloy and precise machining create a reliable seal that holds up against vibration, hydraulic pressure, and constant exposure to salt, spray, and heat. You will spend less time worrying about leaks and more time enjoying the simple satisfaction of a trim system that responds exactly when you ask it to.

The difference shows up in day-to-day use: easier trailering, cleaner hole shots, smoother top-end runs, and better control when navigating shallow routes. It is a small component, but it brings back the feel that makes boating enjoyable.

Why Buy OEM

There are plenty of hydraulic parts on the market, but only a genuine Mercury Marine part number 8M0021648 gives you the exact tolerances your system was built around. This is especially important in trim and tilt components, where a few thousandths of an inch can affect pressure, sealing, and long-term system integrity.

OEM means it fits right the first time, holds pressure the way the pump expects, and keeps your hydraulic system performing season after season. Aftermarket components may look similar, but they rarely match the durability, machining quality, or corrosion resistance demanded in marine environments. When you are relying on trim to run safely and comfortably, OEM is the practical, no-nonsense choice.

FAQ

Q1: Which Mercury engines does this end cap fit?

It fits a wide range of 110–300 horsepower Mercury and Mariner outboards, including EFI, Pro XS, DFI, SeaPro, and select Verado models.

Q2: What makes this different from aftermarket versions?

OEM precision. The machining, sealing surfaces, and alloy quality match Mercury’s original engineering.

Q3: How can I confirm it is the correct part for my engine?

Match your engine model and serial number with Mercury’s parts listing or your service manual.

Q4: Is this safe for saltwater use?

Yes. The alloy and coating are designed for demanding marine environments.

Q5: Is installation something most boat owners can do?

With basic hydraulic knowledge and the right tools, many owners install it themselves. Others prefer a technician. Either way, the part fits cleanly.