Yamaha Gear Lube for Outboard Engine Gearcase Components

Yamaha Lower Unit Marine Gear Oil Resources and Information

Yamaha gearcase lube oil is a superior marine lubricant designed to to protect Yamaha outboard lower unit gearcase components. PartsVu.com’s selection of Yamaha gearcase lube is formulated to protect gearcase components even while outboards operate at high speeds for extended periods in fresh or saltwater. Applications include robust rust and corrosion inhibitors to extend lower unit life.

Certified Yamaha marine gear oil is formulated to protect your Yamaha lower unit against rust and corrosion, extending the operation of your Yamaha outboard engine. Our selection of lower unit marine oil comes in quarts and gallons, as well as in convenient gear lube kits to make servicing your Yamaha lower unit easy. 

We stock a complete range of Yamaha outboard parts to service your Yamaha outboard engine. Looking for other Yamalube products? Browse this page for our selection of Yamalube marine motor oil, Yamalube fuel additives, Yamalube marine grease, and more!

We also regularly release new, helpful resources like:

• Yamaha Outboard Specs & Capacities Chart

• Yamaha Outboard Maintenance Parts Charts

Yamaha Gear Lube for Outboard Engine Gearcase Components FAQs

Why lubricate my Yamaha lower unit gearcase components? 

The gears inside your Yamaha lower unit are constantly turning, and the only protection they have is the lower unit lubricant you use. Its job is to form a micro-thin film between the metal component parts to keep them from actually touching. Under the large loads, these gears exert, proper lubrication requires extreme resistance to pressure, foaming, and molecular shear. And, since the lower unit operates underwater, its lubricant also has to be capable of maintaining necessary lubricity even when a significant amount of water is present, should some leak inside. Ordinary gear lubricant can’t do all of this; so always avoid automotive or tractor gear oils. Use a quality, superior marine lubricant-based formula, like Yamalube Marine Gearcase Lube. It can perform all of these required protection and lubrication duties, even with a full 10% of water present. There’s even an HD formula, to meet the special needs of Yamaha’s top-of-the-line V MAX SHO, 4.2L V6 Offshore, and 5.3L F350 V8 outboard lower units.

How do I perform a lube change on my Yamaha outboard?

Yamaha recommends replacing your lower unit lubricant after the first 20 hours for a new outboard, then every 100 hours after that. Also, if your Yamaha gearcase lube is milky in color or smells or looks burnt when you’re checking it, it’s time for a change. To do it yourself, place a pan under the bottom drain screw, remove the screw, and then remove the upper vent screw on the side of the lower unit. Allow all of the lubricant to drain into the pan. While you’re waiting, check the drain screw. It’s magnetic, so any metal particles or shavings present in the lubricant will be attracted to it. Fine metallic dust is normal, but if you find larger chips of metal on the screw or in the pan as the lubricant drains, have your local Yamaha Marine dealer check for possible internal damage. Also at this time, replace the small crush washer present on each screw (commonly known as “drain plug gaskets”). If you don’t see one, it may still be adhering to the outboard. Use a pick to pull it free, as these must be located, discarded, and replaced each time these screws are removed.

These drain screw crush washers serve as gaskets and are not reusable. They are the main source of protection against water intrusion into the lower unit, which can cause catastrophic dilution of the lubricant. Do NOT try to save a few pennies here. Yamaha lower units are very expensive. It’s best to always have some extra drain plug gaskets on hand. Get all of the parts and lube you need for the job with a Yamalube Gear Lube Kit.

Once all the lube has drained, refill the lower unit by threading the appropriate fitting into the lower unit drain screw opening (on the bottom of the bullet) and slowly pumping in fresh Yamalube Marine Gearcase Lube or Lubricant HD. Once you see this new fluid seeping out of the upper vent screw hole, stop and wait 5 minutes, then very slowly continue pumping until it seeps from the upper vent screw hole again. At this point, replace the vent screw with a new crush washer installed, and tighten it according to manufacturer specifications. Remove the fitting attached to the drain screw opening, and quickly re-install the drain screw with the new crush washer installed. Tighten to factory specifications.

You may choose to do these procedures yourself, or you can have your authorized Yamaha Marine dealer do them for you. Either way, performing them is important for proper continued operation and your continued satisfaction and enjoyment.

Check out PartsVu’s selection of handy and ready-to-use Yamaha Gear Lube Kits!

How do I ininspect my Yamaha lower unit for signs of wear?

Visually inspect the exterior of your Yamaha lower unit for any signs of damage every time before you go out. If you fish, it’s a good idea, every fifty hours or so (or when necessary whichever occurs first), to remove the propeller and check for any fishing line or other debris that may be wrapped around the propeller shaft, which can cut into prop shaft seals and potentially allow water to enter the gearcase. If found, visually inspect the prop shaft seals for damage or leakage. Then check the color of your lower unit lubricant by cracking the “drain screw” on the bottom of the bullet and the “vent screw” on the side of the lower unit. Allow a small amount to drain into a clean container. If the lubricant is milky in color, you’ve got water in the lubricant. Have the lower unit seals inspected by your Yamaha Marine dealer through a pressure test, and if necessary, have the seals replaced. Pressure testing a lower unit is best performed by an authorized Yamaha Marine dealer, because depending on findings, it may be necessary to disassemble the lower unit for further inspection.

Since you are in the neighborhood – take the opportunity to lube your prop shaft, bearings, and any other wear points – Yamalube Marine Grease is good – use it!

How do I service my Yamaha outboard lower unit?

Yamaha lower unit gear lube is drained by removing the lower drain screw first and then the upper plug vent to allow air in. On most models, both plugs are clearly visible on the lower unit, but on models with low water pickups, the forward pickup will need to be removed to access the drain plug. Use a properly sized screwdriver assisted by a wrench if necessary to loosen these screws which should be pretty tight. An impact driver and hammer may be needed depending on who serviced your engine last. The drain screw has a magnetic tip, so inspect the upper vent plug after removal to see if heavy deposits exist. Some fine shavings are normal, but chunks or a large quantity of metal is cause for further inspection. Have a drain pan and extra rags handy as gear lube will begin running down the skeg as soon as you remove the upper vent plug. Be sure to collect the fiber gaskets from both plugs after removal, as these are not reusable and should be discarded.

Why should I purchase a Yamaha marine gear lube kit?

Of course, changing your gear lube is a part of regular service intervals. Having the parts and products on hand (like Yamalube gear lube) makes performing this critical maintenance step a breeze.

Increase your Yamaha outboard lifespan

From the moment your Yamaha outboard first hits the water, your outboard motor will start to degrade. If you use your engine is used heavily, allowed to corrode, stored improperly, and not properly maintained (see below), your outboard’s lifespan will be significantly shortened. Yamaha makes a diverse line of high-performing outboard motors that will perform many years of service before needing to be replaced. However, your commitment to regular maintenance is required to achieve optimal performance and a long lifespan. For example, not regularly changing your lower unit’s oil with Yamalube or gear lube kit can seize your engine, costing thousands in repairs and degrading its overall performance. That’s why having a Yamaha marine gear lube kit on hand is a wise and cost-effective long-term strategy.

DIY repairs save you time and money

We’ve all heard the saying “A boat is a hole in the water you throw money into.” The truth is that some of the most expensive outboard repairs can be avoided with proper maintenance. Having all the necessary parts and products on hand saves you time and money. By going the DIY route, you can change your oil, replace routine parts, and lube up your engine in a matter of hours. And, all for substantially less money than would be required if you took your boat to your local marine mechanic.

Marine gear lube is the lifeblood of your Yamaha outboard

Oil and grease are the primary lubricants that keep your outboard in the water and out of the repair shop. If it’s time for maintenance, or you detect oil that is milky in color, smells burnt, or looks darker than usual when checking it, it’s time for a change. That being said, the choice of oil matters. One of the most commonly-asked questions about lower unit oil is, “Can I use regular gear oil in my lower unit?” The answer is no. Lower unit oil is made with emulsificantes – that is to say that lower unit oil and gear oil has additives that help absorb moisture to prolong engine performance. Because the lower unit spends a significant portion of its usage in water, emulsificantes ensure the proper longevity and performance of your Yamaha outboard motor.

What Yamaha lower unit oil type is right for my outboard motor?

The appropriate type of Yamaha lower unit oil for your outboard motor can depend on several factors, including the model and year of your engine. It is important to consult your owner's manual or consult with a Yamaha dealer or qualified marine technician to determine the correct type of lower unit oil for your specific engine.

That being said, Yamaha recommends using their Yamalube 4M FC-W synthetic blend oil for their four-stroke outboard motors, and Yamalube 2M TC-W3 mineral-based oil for their two-stroke outboard motors. These oils are formulated with additives that provide superior wear protection, prevent corrosion, and help maintain proper viscosity under a variety of conditions.

It is important to use the recommended oil for your engine to ensure optimal performance and longevity, and to follow the manufacturer's recommended oil change intervals. Additionally, it is important to use the correct oil level and avoid overfilling, as excess oil can cause issues such as foaming, overheating, and loss of performance.

What’s the best lower unit gear oil for Yamaha outboard engine maintenance?

Yamalube is the recommended lower unit gear oil for Yamaha outboard engine maintenance, as it is specifically formulated for use in marine applications and meets the requirements of Yamaha's stringent standards. However, there are other high-quality lower unit gear oils on the market that can be used in Yamaha outboard engines, such as Mercury Marine's Quicksilver Premium Gear Lube and Pennzoil Marine Premium Plus Gear Lube. It is important to use a gear oil that meets the manufacturer's specifications and to follow the recommended maintenance schedule for your particular outboard engine.

How much does Yamaha gear lube for outboard engine gearcase components cost on average?

The cost of Yamaha gear lube for outboard engine gearcase components can vary depending on the quantity, location, and retailer. On average, a quart of Yamalube gear lube for outboard engine gearcase components can cost between $15 to $25 USD, while a gallon can cost between $40 to $70 USD. However, it is important to note that prices can vary based on availability and market conditions. It is always recommended to compare prices from different retailers and purchase from a reputable dealer to ensure you are getting a genuine product that meets the manufacturer's specifications.

What oil is used in a Yamaha outboard gearbox?

Yamaha recommends using Yamaha Genuine Gearcase Oil or an equivalent high-quality marine lower unit gearcase oil that meets or exceeds Yamaha specifications. The recommended viscosity for Yamaha outboard gearcase oil is 80W-90.

It is important to use the appropriate oil for your specific outboard motor to ensure optimal performance, protection, and longevity. Using the wrong type of oil could potentially lead to issues with performance, reliability, or warranty coverage.

What oil goes in an outboard lower unit? / What kind of oil do you put in an outboard gearbox?

Outboard lower units require a specialized marine lower unit gearcase oil to provide the necessary lubrication and protection.

The specific oil recommended for your outboard motor will depend on the manufacturer and model, but in general, most manufacturers recommend using a high-quality marine lower unit gearcase oil that meets or exceeds their specifications.

For example, Yamaha recommends using Yamaha Genuine Gearcase Oil or an equivalent high-quality marine lower unit gearcase oil that meets or exceeds Yamaha specifications. The recommended viscosity for Yamaha outboard gearcase oil is 80W-90.

Can you use gear oil in a outboard lower unit?

Yes, you can use gear oil in an outboard lower unit, but it is important to use a marine-specific lower unit gearcase oil that is designed to withstand the harsh marine environment.

Gear oil is formulated differently from engine oil and is designed to provide the necessary lubrication and protection for gears and other components in the lower unit of an outboard motor. Using the wrong type of oil or lubricant could potentially cause damage to the gears or other components and could impact the performance and longevity of the outboard motor.

It is important to always consult your outboard motor's owner's manual or review the manufacturer's recommendations to determine the appropriate type and specification of gearcase oil to use.

What can I use instead of Yamalube gear oil?

It is always recommended to use the manufacturer's recommended gear oil in your outboard motor, which for Yamaha is Yamalube gear oil. However, if you cannot find Yamalube gear oil or if it is not available, you can use other gear oils that meet the same or similar specifications.

For Yamaha outboards, the recommended gear oil is typically an SAE 90 weight or 80W-90 weight gear oil that meets or exceeds API GL-4 specifications. Some suitable alternatives to Yamalube gear oil include:

• Mercury Marine High-Performance Gear Lube

• Quicksilver High-Performance Gear Lube

• Evinrude Johnson Hi-Vis Gearcase Lubricant

• Mobil 1 Synthetic Gear Lube LS 75W-90

It is important to always check the specifications of the alternative gear oil to ensure it is compatible with your outboard motor and meets the required specifications.

Is there a difference between marine gear oil and regular gear oil?

Yes, there is a difference between marine gear oil and regular gear oil. Marine gear oil is specially formulated to meet the unique demands of marine environments, which include exposure to saltwater, extreme temperatures, and high humidity levels.

Marine gear oil typically contains additives that provide improved corrosion protection, water resistance, and anti-foaming properties, which are important factors in marine applications. Additionally, marine gear oil is often rated to meet specific industry standards, such as NMMA FC-W or TC-W3 standards, which ensure that the oil is suitable for use in marine engines and will provide adequate protection against wear and tear.

On the other hand, regular gear oil is designed for use in automotive applications and may not have the same level of protection or be suitable for use in marine environments. It is important to use the appropriate gear oil for your outboard motor to ensure its optimal performance and longevity.

What is Yamaha lower unit oil for my Yamaha outboard motor? / What is Yamalube lower unit oil? / What is Yamaha outboard gear oil? / What is Yamalube gear oil? / What is Yamaha outboard gearbox oil?

Yamaha lower unit oil is a type of lubricant specifically formulated for use in the gearcase components of Yamaha outboard engines. It is designed to protect the gears and other protect gearcase components from wear, corrosion, and damage caused by high speeds, extended periods of use, and other harsh operating conditions.

What is the best lower unit gear oil for Yamaha?

The best lower unit gear oil for Yamaha engines is typically the oil recommended by Yamaha themselves, which is Yamalube gear oil. This oil is specifically formulated to provide the best possible protection and performance in Yamaha engines, and is designed to meet or exceed Yamaha's strict quality and performance standards.

What is a gear lube kit?

A gear lube kit is a package that typically contains everything you need to change the lower unit gear oil in your outboard engine, including the oil itself, a drain plug, a vent screw, and any necessary gaskets or other fittings.

What is a lower unit lubricant?

A lower unit lubricant is a specialized oil or grease that is designed to lubricate the gears and other components of the gearcase in an outboard engine. It is formulated to provide superior protection against wear, corrosion, and damage, and is designed to withstand the harsh operating conditions of an outboard engine.

What is a magnetic tip?

A magnetic tip is a feature of some drain plugs and other fittings used in outboard engines that helps to catch and hold onto any metal debris or shavings that may be present in the oil or lubricant. This can help prevent damage to the gears and other components, and can help to extend the useful life of the engine.

What is a fiber gasket?

A fiber gasket is a type of gasket made from compressed fibers or other materials that is used to create a seal between two surfaces in an outboard engine. These gaskets are designed to be durable and long-lasting, and are often used in applications where high temperatures or pressures are present.

What is a drain plug gasket?

A drain plug gasket is a small gasket that is used to create a seal between the drain plug and the gearcase of an outboard engine. These gaskets are designed to be replaced each time the oil is changed, in order to ensure a secure and leak-free seal.

What is an upper vent screw?

An upper vent screw is a screw located on the top of the gearcase of an outboard engine. It is used to vent air from the gearcase during oil changes and refills to prevent air pockets from forming, which could cause damage to the gears and other components.