Break In

Is metal on the magnetic drain plug normal at the first oil change?

A fine, glitter-like or fuzzy deposit on the magnet is normal through the first 10 hours - that's the bearings, races and gears wearing in together. What's worth a closer look is larger chips or a heavy quantity. Send us a photo of the plug along with your unit serial number and hours and we'll help you tell the difference.

My first gear lube change came out green or opaque - is there water in it?

Usually not. We use an assembly grease during the build that's typically blue in colour, and once the unit is filled with lube and run, that grease mixes in. Seeing a coloured, cloudy lube at the very first change is normal. If you're not satisfied that's the explanation, a pressure or vacuum test to a maximum of 15 psi held for 15 minutes will tell you whether the gearcase seals are sound - and you're welcome to send us photos.

My new Bravo drive shifts hard - will that improve?

Bravo drives are tight to shift when the engine isn't running, so check whether you're testing it that way first. Our drives are also a "high bump" version of the Bravo, so a firm shift in and out of gear is expected and normal in operation. Drives do loosen up after break-in. It's still worth verifying your shift cables are in good condition and moving freely.

My new lower unit is louder than my old one - is that normal?

Yes, that's expected at first. The gears haven't been broken in to one another yet, and the bearings, races and gear faces all still have to wear together. Once it goes through proper break-in - and particularly once it runs under load - we expect it to quiet down to a normal level. This is exactly why the break-in procedure matters on any new mechanical assembly.

There's a clunk when I shift into gear and spin the prop out of the water - is something wrong?

That's normal out of the water. With no water load there's no pressure on the propeller to keep the clutch engaged smoothly, so you'll hear and feel it engage. It's much more noticeable with a heavier stainless prop than with aluminium. If it behaves normally once the boat is in the water under load, there's no issue.

What is the break-in procedure for a new SEI lower unit or drive?

For the first 5 hours, don't hold a constant RPM - vary it every 5 minutes or so - and don't exceed 75% throttle. Shift into forward and reverse at least 10 times during those first 5 hours. Between 5 and 10 hours, do short runs at full throttle. After 10 hours you can resume normal operation, and you must change the gear lube somewhere between 10 and 20 hours. Keep the load light and start slow and low for the first few hours.

What tags come with a Yamaha lower unit and what do they tell me?

There are two tags on the prop shaft. One carries the break-in instructions and the other states the unit is shipped without gear oil. Beyond installation, filling it with marine gear lube is the one thing you must do before running it. When mounting, pay attention that the gearcase and shift linkage spline up and everything goes together without binding.

What's the break-in procedure for a new lower unit or drive?

For the first 0-5 hours, run at lower RPM and gradually work up. From 5-10 hours, keep full-throttle bursts to just a few minutes per hour. Then change the gear lube at 10-20 hours - don't skip that first change. A little glitter-like metal on the magnetic drain plug at that first change is normal.

What's the most common cause of premature lower unit failure?

By a wide margin it's improper break-in, or the gear lube not being changed often enough and becoming burnt and gritty. The change at 10 hours after break-in is the one we see skipped most often, and skipping it is what turns a healthy unit into a failed one. Follow the break-in tag and do that first change on time.

Where do I find the break-in instructions for my unit?

They come with the unit - there's a tag attached to the prop shaft with the break-in procedure printed on it. If that tag has gone missing, call or text us at 813-925-7127 and we'll send the procedure over.

Filling

How do I fill a sterndrive with gear lube correctly?

Always fill from the bottom up so you don't trap air. Pump lube in through the very bottom plug until it comes out of the top plug on the upper, then install that top plug and keep pumping until the lube shows at the proper level in the gear lube bottle. Then remove the pump and install the bottom plug. Getting to the full level matters - an underfilled unit can fail early, and a single quart is definitely underfilled on a sterndrive.

Is there a third vent plug on the Suzuki lower unit?

Yes, and this catches people out. We've seen Suzuki units come back underfilled because the third vent plug wasn't used during filling - the unit reads as full without it but isn't. Make sure you're using all the fill and vent points when you fill it, because an underfilled gearcase can fail early.

First Start

How high should the water be for the first start after fitting a new unit?

With the boat sitting in the water off the trailer you should be fine in theory, but we'd keep it on the trailer with the straps on so you can get higher than the normal waterline - aim for an extra 6 inches to a foot depending on the boat. It's also worth putting a little dish soap on the impeller when you install it so it's slippery on that first dry turn.

Gear Lube

Can I use MerCruiser or Quicksilver OEM gear lube and grease on an SEI drive?

Yes, no issues at all - OE gear lube and OE grease are both fine on our outdrives. You don't need a special SEI-branded fluid. We do sell the correct gear lube and a fill pump if it's easier to add it to your order.

Do I have to keep using SEI-branded gear lube?

No. You can use any GL-4 (semi-synthetic) or GL-5 (full synthetic) rated 80/90 or SAE 90 marine gear lube in our units, exactly as with the OE gearcases. We sell our own lube and the drain washers if it's convenient to add them to an order, but the drain gaskets are the same ones used on almost all lower units and are widely available.

Gear oil is leaking from the hole on the side of my lower unit - what causes that?

Start by draining the gear lube and pressurising the gearcase to 10-15 psi to confirm where it's actually escaping. When they leak from that side hole, the source is most often up under the water pump and driveshaft area rather than at the point you can see. Let us know your purchase date and serial number and we'll check whether it's within the warranty period.

If water got into the gear lube, does it damage the bearings?

It can. Most marine-grade gear lube will emulsify with water, so while the unit is running every bearing is being fed the same diluted, poor-quality lube. When you stop, it separates over time and the water settles to the bottom - which is where the lower bearing sits. The longer it runs that way, the more likely there's damage.

My gear lube is milky or watery - what should I do?

That's water intrusion, and the first step is to find where it's getting in. Drain the lube, then pressure test the gearcase to 10-15 psi and spray soapy water around the seals - the bubbles will show you the leak. On a sterndrive, a failed bellows is a common cause rather than the unit itself. Get the SEI serial number off the unit and call us at 813-925-7127 so we can check your warranty status and start a claim if it's covered.

What gear lube should I use in an SEI unit?

Quicksilver or Mercury High Performance gear lube is what we point people to. Specification-wise we recommend an 80/90 semi-synthetic rated GL-4, or a straight SAE 90. All units ship dry, so it needs filling before you run it.

What gear lube should I use, and how much?

Use Mercury or Quicksilver High Performance gear lube (a straight ~90 weight) - as long as it says "High Performance" you're good. Fill to the top vent hole with the drive/motor level; an underfilled unit can fail early. Capacities vary by model, so check your unit's spec or ask us.

Maintenance

How often should I pull the outdrive for service?

Once a year. The main reason is the water impeller, but with the drive off it's also the right time to check the transom components and grease the U-joints. Marine-grade grease is preferred, though most tube greases will do the job. For gear lube, stay with a marine-grade 80/90W or SAE 90.

How often should I replace the water pump impeller?

Every year or every 100 hours, whichever comes first - and sooner if you've been running in sand or silt. Replace the whole water pump kit rather than just the rubber impeller: the kit contents are plastic and the base of the pump also seals the driveshaft, so renewing one part of an aged assembly is false economy. While you're in there, inspect the driveshaft collar for hairline cracks.