6 Best Aviation Grade Greases For Landing Gear Struts

A reliable landing gear strut is the unsung hero of every smooth touchdown, whether navigating backcountry airstrips or landing on a paved runway. Maintaining these components ensures that shock absorption remains consistent and that structural integrity isn’t compromised by friction or debris. Selecting the correct aviation-grade grease is the most critical step in preserving the lifespan of these high-stress assemblies.

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AeroShell Grease 22: Best Overall Choice

AeroShell Grease 22 is a microgel-thickened, synthetic hydrocarbon oil grease that stands as the industry standard for a reason. Its versatility across wide temperature ranges makes it an exceptional choice for general aviation aircraft that face unpredictable weather shifts. It provides excellent anti-wear properties and load-carrying capacity, ensuring that internal strut components remain protected during heavy landings.

This grease is particularly well-suited for those who fly in varying climates, from sweltering summer heat to near-freezing mountain descents. Because it resists water washout and maintains its consistency under high mechanical loads, it simplifies the maintenance routine for the average pilot. If you prioritize reliability and broad compatibility, this is the grease that belongs in your hangar.

Mobilgrease 28: Top Synthetic Aviation Grease

Mobilgrease 28 is designed specifically for high-speed, high-temperature applications, making it a favorite for performance-oriented aviation. This clay-thickened synthetic grease excels at protecting against wear and corrosion in components subjected to heavy stresses and extreme temperature variations. Its wide operating range ensures that the grease does not harden in the cold or thin out excessively in the heat.

For aircraft operators who demand the highest level of protection against oxidation and shear, Mobilgrease 28 is the clear winner. It is highly recommended for struts that see heavy, consistent usage in challenging environments. It is a premium investment, but for those operating in demanding conditions, the peace of mind is well worth the cost.

Royco 22CF: Best for Extreme Temperatures

When operating in climates that hover at the edge of operational extremes, Royco 22CF provides a specialized advantage. This synthetic, wide-temperature-range grease is engineered to maintain its performance characteristics in both biting cold and intense heat. It effectively prevents the “stick-slip” motion that can plague landing gear in arctic or desert conditions.

Choosing Royco 22CF is a smart move if the aircraft lives in high-altitude environments or regions with dramatic seasonal temperature swings. While it may be overkill for a casual weekend flyer in a temperate zone, its ability to remain stable under thermal stress is unparalleled. Invest in this option if environmental extremes are a standard part of the flight plan.

AeroShell Grease 33: Best Universal Pick

AeroShell Grease 33 represents the pinnacle of modern anti-corrosion technology in the aviation lubricant sector. It was developed to meet the demands of newer airframe designs that require superior protection against structural wear. Its universal appeal stems from its ability to provide exceptional performance across a massive array of airframe components, including landing gear struts.

This grease is the ideal choice for those who prefer to keep their inventory simple without sacrificing protection. It is highly resistant to water washout and provides a robust barrier against the elements. If you want a single, high-quality solution that works effectively across almost every grease-lubricated point on the aircraft, this is the primary choice.

Nyco Grease GN 144: Best Mil-Spec Option

Nyco Grease GN 144 is the heavy-duty workhorse designed to meet stringent military specifications. It is highly resistant to water, oxidation, and heavy mechanical loading, which makes it an ideal candidate for rugged terrain operations. This grease is specifically engineered to perform in the harsh conditions often encountered during off-airport or rough-field landings.

This is the right choice for the pilot who routinely pushes the aircraft into demanding environments. Its durability under heavy pressure means less frequent maintenance intervals during long-term field operations. When the mission profile requires gear that will not fail under stress, trust in the specifications provided by GN 144.

Mobil Aviation SHC 100: Best For Bearings

While landing gear struts often focus on shock absorption, the associated bearing assemblies require specialized lubrication to remain fluid and responsive. Mobil Aviation SHC 100 is a synthetic grease that offers a high viscosity index, allowing it to maintain an optimal film thickness even under extreme load. This reduces the risk of pitting and scoring on internal bearing surfaces.

If your maintenance routine focuses on the long-term health of mechanical pivot points and bearings within the landing gear assembly, prioritize this product. Its synthetic base provides excellent low-temperature torque properties, which facilitates easier operation during cold starts. It is a highly focused lubricant that excels where other general-purpose greases might fall short.

How to Choose the Right Landing Gear Grease

The primary factor in selecting a grease is the manufacturer’s maintenance manual. Always prioritize the specifications outlined by the aircraft designer, as these dictate the base oils and additives required for specific seals and metals. Disregarding these requirements can lead to seal degradation, swelling, or premature failure of the strut assembly.

Consider the operational environment as a secondary filter. Aircraft that spend significant time near saltwater require greases with high corrosion-inhibiting properties. Conversely, aircraft operating primarily in dusty or sandy environments need a grease that seals effectively and doesn’t trap abrasive particles.

• Paved Runways: Standard high-performance synthetic grease is usually sufficient.
• Rough/Unimproved Fields: Prioritize heavy-duty, water-resistant, and high-load capacity greases.
• Cold Climates: Ensure the grease is rated for low-temperature fluidity to prevent gear lock.

Proper Application Techniques for Gear Struts

Precision is essential when applying grease to strut assemblies. Over-greasing is a common mistake that can blow out delicate seals or create a mess that traps debris. Use only the recommended amount of lubricant, ensuring that old, contaminated grease is pushed out and replaced by fresh product.

Clean the zerks and surrounding areas thoroughly before application. Introducing dirt into the strut during the greasing process creates an internal grinding paste that accelerates wear. Once applied, cycle the gear if possible—or perform a walkaround inspection—to ensure the lubricant has settled into the necessary friction points.

Recognizing Signs of Wear on Your Gear Struts

Regular inspection prevents the catastrophic failure of landing gear components. Keep an eye out for leaking hydraulic fluid, which often manifests as a wet, oily sheen on the piston. If the strut fails to hold its rated extension or exhibits a “bouncy” sensation during taxiing, it indicates internal wear or a loss of nitrogen pressure.

Check for pitting or oxidation on the chrome-plated strut shaft. Small rust spots are precursors to seal damage and leaks. If the landing gear feels “sticky” or produces audible groaning, the internal bushings may be dry or worn, necessitating an immediate breakdown and inspection.

The Dangers of Mixing Different Grease Brands

Mixing incompatible greases is one of the fastest ways to cause mechanical failure. When different thickener systems—such as clay, lithium, or synthetic-based greases—interact, they can thicken or thin out unpredictably. This chemical reaction may cause the grease to lose its lubricating properties entirely, leading to catastrophic friction and overheating.

If a different type of grease must be used, the old grease must be completely purged from the system. It is never acceptable to simply add new grease over the old without confirming chemical compatibility. Sticking to one high-quality brand and type simplifies maintenance and ensures that the protective barrier on your gear struts remains intact.

Maintaining your landing gear struts is an investment in safety that rewards the pilot with reliable performance on every flight. By choosing the right grease and adhering to a disciplined maintenance schedule, you minimize the risk of mechanical issues while on the ground or in the air. Keep those struts serviced, keep your head in the clouds, and enjoy the adventure.