Operating an outboard motor requires regular maintenance, and one of the most critical procedures is lubricating friction knots. Many watercraft owners wonder how to syringe an outboard motor to prolong its life and avoid costly repairs. Incorrectly selected consistency or lubricant chemical composition can lead to rapid wear of gears, corrosion and even jamming of the mechanism.
In this article, we will discuss all the nuances of the choice transmission-lubricantsIf you look at popular brands, and if you can use car analogs, the right gearbox and screw hub maintenance is a guarantee that your engine will work like a clock for many navigation seasons.
Why you need a syringe lubricant for a gearbox
The main function of lubrication in the gearbox of the outboard motor is not only to reduce friction between the gear teeth, it also serves as a function. coolant Because the gearbox is submerged in water and under load, the lubricant must have a unique set of properties that are not required by conventional machinery.
Unlike the oil in the internal combustion engine, transmission-lubrication It works under high pressure and impact conditions, especially when changing gears, and it must maintain its viscosity both when starting coldly and when heating to high temperatures, and if you ignore this aspect, water can penetrate the body through the glands, causing emulsification and loss of lubricating properties.
And also, the quality lubricant contains special additives that prevent the oxidation of metals. In seawater, corrosion occurs very quickly, so that's why it's so important to know that it's not so good. corrosion-proofing Using the wrong composition can cause the gears to rust even with brief contact with water.
Change the lubricant in the gearbox at least once a year, even if the motor is not used intensively, this will help to detect water intake at an early stage.
Key specifications of lubricants
When choosing what to use a outboard motor, you need to look at the product specification. Conventional lithium lubricants, often used in cars, may not be suitable because of insufficient adhesion to the metal in the aqueous environment. You need a material that is not washed away by water and has high stickiness.
The most important parameter is water-resistanceThe lubricant must form a strong film that does not dissolve or wash out even during prolonged exposure to water, and temperature stability is also critical: the composition must not flow when the gearbox is heated and must not thicken so much as to prevent the shafts from rotating in the cold.
Modern manufacturers add molybdenum disulfide or graphite to improve the anti-sharp properties, creating a layer that prevents direct metal contact with metal under extreme loads. hypoid-transferred This is particularly relevant.
Can different lubricants be mixed?
Mixing lubricants from different manufacturers and types of thickeners is strongly discouraged. Chemical reactions between components can lead to the dissection of the mixture, loss of viscosity and the formation of hard lumps that clog the lubrication channels and damage the omentums.
Top of the best lubricants for outboard motors
The market offers a variety of specialized products designed specifically for water technology, and the leaders in this field are marine chemicals brands that take into account all the requirements of operating in an aggressive salty environment.
- 🌊 Mercury Marine Grease - Classic lithium-based lubricant with molybdenum disulfide, great for gearboxes and screw hubs, has high water resistance.
- ⚓ Yamalube Marine Grease The versatile composition developed by Yamaha engineers is perfectly combined with the seals of the engines of this brand and protects against corrosion.
- 🛡️ Liqui Moly Marine Grease German product with excellent temperature specifications, often used for both gearboxes and bearing units.
- 🔧 Tohatsu Genuine Grease Specialized lubricant for Tohatsu and Nissan Marine engines, providing a long service life of gears.
When choosing a specific brand, it is better to focus on the recommendations of the manufacturer of your engine. sea-lubricants It is also acceptable to use well-known brands if they meet the required quality standards, the main thing is to avoid cheap analogues without clearly specifying the composition.
Can you use car analogues?
Motor owners often ask if expensive specialized lubrication can be replaced with more affordable automotive analogues, such as: Litol-24 The answer to this question is ambiguous and depends on the operating conditions of your vessel.
Automotive lubricants, such as Litol-24They have good lubricating properties, but they're designed to work in the air, and if they come into contact with water for a long time, they can wash out, leaving the rubbing parts unprotected, and this is especially dangerous for gearboxes, where the probability of water getting in is high.
Lubricants for shrubs (graphite or molybdenum) are often black and contain particulate matter. not recommended Because of the risk of damage to the end seals (oils) by abrasive particles, they may also be less resistant to emulsification with water.
⚠️ Attention: Use of automotive lubricants in the gearbox of the outboard motor is permissible only in emergency cases for a short period of time. For permanent operation, be sure to use specialized compounds marked "Marine" or "Water Resistant".
If you still decide to use an automotive analog, choose products with maximum water resistance and high drop point. However, remember that saving on lubrication can lead to the cost of repairing the gearbox, which will be ten times higher than the cost of a tube of quality droplets. sea-lubricant.
Instructions for replacing lubricant in the gearbox
The process of replacing the lubricant in the gearbox is quite simple and does not require complex equipment, except for a special syringe, and it is important to perform this procedure on a warm engine or immediately after operation, while the old lubricant is still warm and liquid.
First, you need to put the boat upright or use a motor bracket. Find two lower unit plugs, the top and the bottom, which usually have conical threads and sealing rings. Before you unscrew, prepare a wastewater drain tank.
☑️ Preparation for grease replacement
Turn the bottom plug out and let the old lubricant leak out. If the lubricant is a "milk coffee" or emulsion color, it's a sign of water getting in. In this case, you should wash the gearbox with a special wash fluid or a new grease before filling. After draining, insert the syringe nose into the bottom hole and slowly pump the new lubricant until it starts to come out of the top hole.
Twirl the top stopper without removing the syringe, then quickly remove the syringe and twist the bottom stopper, which avoids the formation of air traffic jams inside the gearbox body, and make sure that the occultation rings on the corks are intact and lubricated.
The main rule: the lubricant is always pumped from the bottom up to displace the air and completely fill the volume of the reducer without voids.
Maintenance of the screw hub and other nodes
In addition to the gearbox, lubrication is required for the propeller hub, which contains slits that the screw can turn over when it hits an obstacle (the torque limiter system), and the lubricant here prevents the screw from sticking to the shaft and protects the slits from corrosion.
For the screw hub, thicker compositions are often used, sometimes with antifriction additives. slurIt is applied in a thin, uniform layer on the slats part of the shaft and the inside of the screw sleeve.
Gas and reverse control cables are also lubricated if they are not Teflon-coated, and for this purpose, spray lubricants are available that penetrate the cable braid, and regular processing of the cables ensures smooth running of the control lever.
| Lubrication knot | Type of lubricant | Frequency | Features |
|---|---|---|---|
| gearbox | Transmission (Gear Oil) | 1 time per year / 100 motor hours | Emulsion testing |
| Spin hub | Consistent (Grease) | 1 time in season | Protection against quilting |
| Shaft scum | Special grease for slitches | Every time the screw is removed | Thin layer |
| Control cables | Aerosol penetrating | 2-3 times in season | Before the grease at the ends appears |
Frequent errors in service
One of the most common mistakes is to ignore the condition of the sealing rings on the drain plugs. The rubber blubbers and cracks over time, which leads to water suction. Always inspect the rings and change them at the slightest sign of wear. The cost of a new ring is negligible compared to the repair of gears.
Another mistake is to use a dirty syringe, and if you have left any residue of old lubricant or sand in your syringe, you will put the abrasive inside a clean gearbox, always wash the tool thoroughly, or use disposable cartridges, and cleanliness in hydraulic and mechanical parts is the key to their long life.
⚠️ Attention: Never try to shove the lubricant into the gearbox with force if it doesn't come in. This could indicate clogging of the vent or the presence of an air plug. Excessive pressure can damage the glands.
Don't forget that visualization The level of lubrication is also important. If the next time you replace the lubricant, the amount of lubricant that has leaked is much less than the amount that has been poured, it can be leaked, and vice versa, if the lubricant is larger, then the reducer has got water.
What to do if the lubricant is blackened?
Blackening of the lubricant in the gearbox is normal for the waste material due to the fine metal shavings from the grinding of the gears. Anxiety should be struck if the lubricant has changed its consistency (became liquid) or color to milk.
Questions and Answers (FAQ)
How often should the lubricant in the outboard motor gearbox be changed?
It is recommended to change the lubricant in the gearbox at least once a year, preferably at the end of the navigation before canning for the winter, or every 100 motor hours if the intensity of operation is high.
Can I use solidol instead of a special lubricant?
Solidol is not recommended for use, it does not have sufficient water resistance and is quickly washed out, and does not withstand the high loads of modern gearboxes, which will lead to their rapid wear.
Why does an emulsion flow from the gearbox?
The appearance of an emulsion (lubrication of the color of coffee with milk) indicates that water enters the gearbox, which can be caused by wear of the glands, damage to the occultation rings of the corks or microcracks in the case.
Do I need to wash the gearbox before pouring a new lubricant?
If the old lubricant has no signs of emulsion and foreign inclusions, just drain it and pour a new one, washing is required only in case of water or severe contamination with wear products.