Synthetic Marine Wheel Bearing Grease

Water contamination can be a real problem when trying to keep equipment lubricated and protected. Whether the environment is at paper mills, wastewater treatment facilities, large cargo ships, or even boat trailers and recreational boats, keeping water from washing out the lubricant can be a challenge for most conventional general purpose lubricating greases. For the maintenance mechanic, it is best to take stock of the best synthetic marine wheel bearing grease for dealing with water contamination in your specific environment.

How to Find the Best Synthetic Marine Wheel Bearing Grease

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Superior Water Resistance

The first thing to research is how the grease performed during the ASTM D 1264 Water Washout Test @79C. If the grease in question scored less than 1.5% water washout, then this ranks it as a superior grease for water resistance. Many conventional greases claim to be waterproof greases yet their water washout score is 3% to 7%. This may be sufficient for minor or limited exposure to water contamination. For the extreme environments where water is a constant presence, it is suggested that a grease having less than 1.5% water washout be used.

AMSOIL Synthetic Water Resistant Grease.
AMSOIL Synthetic Water Resistant Grease

Withstanding Extreme Pressure Shock Loads

Water contamination is not the only issue to consider when choosing a superior water resistant grease. There are other factors that a grease must deal with beyond water contamination to make it an effective grease for protecting critical machinery parts.

For example, if the machine is operating in an environment where water is constantly present, yet at the same time the machine is exposed to extreme pressure and shocks loads, then these constant shock loads can ultimately affect the grease’s water resistance performance along with long term protection during shock loads.

So, we must also consider a grease’s ability to withstand extreme pressure shock loads while being constantly exposed to water contamination. The well known industry test for extreme pressure is called the Timken OK Load Test (ASTM D-2509.) A waterproof grease that scores a 70 pound Timken OK Load would be the best choice for extreme pressure conditions.

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When a piece of equipment is exposed to high shock loading and heavy load, it can be said they are functioning at peak or upper level efficiency. There are certain specialty greases on the market that were designed exclusively to score a high Timken OK Load value. Unfortunately, they do not provide the necessary protection from where when the loads are in the more normal range.

In other words, the chemistry is not balanced. It is best when looking at technical data sheets to check the score that the grease rates at during this ASTM D-2266 4 Ball Wear Test. A score < 0.45 mm Scar Diameter illustrates that the grease can protect when loads are more normal.

Withstanding Extreme Operating Temperatures

Another specification that must go hand in hand when choosing a waterproof grease that will be useful in protecting critical machinery parts is the grease’s operating temperature. The first test to look for is the ASTM D-2265 Dropping Point Test. A dropping point > 500 F makes it a grease that can withstand high temperatures. On the low end or cold operating temperature, a -40 degrees Fahrenheit would be a grease that would not harden up and still have the proper consistency to protect critical machinery parts.

Cohesive/Adhesive Properties

The next area to consider would be whether the grease has any cohesive and adhesive characteristics. Having a tacky or stringy consistency would mean the grease would have the capability of providing a tenacious and strong barrier against any damaging contaminants such as dirt, dust, mud, moisture, and water. Also, this tacky or stringy consistency can help during extreme pressure and shock loading, allowing the grease to stay put and protect metal surfaces.

Robust Additive Package

Another area that would help a grease protect against water and other contamination would be what type of additives are used in the formulation. It is important that it have a robust volume of rust and corrosion inhibitors, anti-wear agents, and extreme pressure additives.

Superior Rust Prevention

Since the goal is to find a grease that is resistant to water contamination, it is also important to see how effective a grease can be at preventing rust. The industry standard test for rust preventative is the ASTM D-1743. Typical results are rated as follows: 1A (PASS) is the best or no rust stain. Any result such as 1B, 1C, etc. means there is some rust staining appearing after the test is run. In the case of this article, it is advised that a score of 1A (PASS) (no rust stain) be the choice.

The Finest Synthetic Water Resistant Grease on the Market

AMSOIL Synthetic Water Resistant Grease.
AMSOIL Synthetic Water Resistant Grease

A highly recommended synthetic marine wheel bearing grease is AMSOIL Synthetic Water Resistant Grease. AMSOIL Synthetic Water Resistant Grease is a technically advanced grease engineered specifically for wet duty performance and extreme pressure. Blended together are top of the line high performance synthetic base stock oils and unique calcium-sulfonate complex thickeners.

This waterproof synthetic grease from AMSOIL offers superior mechanical stability, shear resistance, film strength, and adhesion capabilities. It delivers outstanding water washout and spray off resistance for any application or environment where equipment and parts could be exposed to water, ice, snow, and mud.

Outstanding Water Washout and Spray Off Protection

The amazing water resistant performance that AMSOIL Synthetic Water Resistant Grease delivers is due to its exclusive chemistry that includes heavy duty and tenacious adhesive and cohesive chemistry. This unique grease will cling tenaciously to metal surfaces when wet and will hold together when exposed to water. When critical components are exposed to standing or pressurized water, AMSOIL Synthetic Water Resistant Grease offers a tough and impenetrable barrier against water, moisture, and other potential contaminants.

If metal surfaces of components have prolonged exposure to water, then there is a high chance of corrosion and rust forming that can result in damage. To fight and guard against rust and corrosion, AMSOIL chemists have formulated in robust amounts of rust and corrosion inhibitors that seals metal surfaces and chemically fights against corrosion. Whether there is extensive exposure to water, snow, ice, or mud, AMSOIL Water Resistant Grease will provide the maximum in protection against corrosion and rust.

Extreme Pressure and Load Carrying Performance

AMSOIL Synthetic Water Resistant Grease offers superior extreme pressure and shock load protection. Its unique formulation utilizes high performance extreme pressure additives that can withstand tremendous and sustained sudden shock loads and offers the finest protection against wear. This synthetic water resistant grease offers the finest protection for your critical components and protects them against any potential metal to metal contact, even during the most extreme heavy loads.

The Finest Synthetic Marine Wheel Bearing Grease

AMSOIL Synthetic Water Resistant Grease was formulated to meet and exceed the performance standards established by the National Lubrication Grease Institute (NLGI) for wheel bearing applications (GC) and chassis applications (LB).  It can be used effectively in automotive wheel bearings, chassis ,or other applications where and NLGI #2 GC or LB grease has been recommended. Without a doubt, AMSOIL Synthetic Water Resistant Grease is the absolute finest synthetic marine wheel bearing grease.


Overall, an obvious area to investigate is to determine if the waterproof grease can be used in a broad range of applications that encompass load, moisture, heat, impact, etc. Make sure the grease can function properly in areas of application such as U joints, ball bearings, wheel bearings, chassis points, bushings, chains, anti-friction bearings, slides, paper mills, construction equipment, cement plants, logging, trucking, mining, steel mills, water treatment plants, asphalt plants, foundries, automotive, etc. If the grease can protect equipment in all these applications and more, then you’ve found the best waterproof marine grease that is also a multi-purpose lubricant.