A modern car is a complex mechanism with thousands of moving elements subject to friction, high temperatures and aggressive environmental influences. Lubricants in this system they play the role of not just an auxiliary component, but a vital element that ensures the durability of the units and the safety of operation. Without the proper use of specialized compounds, even the most expensive car will turn into a pile of metal in a matter of months.
Owners often confuse the concepts, believing that there is one universal remedy “for everything” that can be smeared on a wheel bearing or applied to the battery terminals. This is a fundamental mistake. Lithium grease, copper anti-friction compound and silicone spray have fundamentally different chemical bases and physical properties. Using the wrong substance can lead to destruction of rubber seals, washing out of the lubricant with water, or, conversely, to its hardening when heated.
In this article we will examine in detail the main types of lubricants, their chemical composition, temperature ranges and specific applications. Understanding the differences between them will allow you not only to save on expensive repairs, but also to extend the life of your car. It is important to select the material based on the operating conditions of a particular unit: load, rotation speed and temperature.
Lithium lubricants: classics for chassis
The most common and recognizable type are lithium greases, often called "Litol" or their more modern analogues. The basis here is a thickener - lithium stearate, which is mixed with mineral or synthetic oil. The main advantage of such compositions is their high moisture resistance and the ability to maintain their properties over a wide temperature range, usually from -20 to +120 degrees Celsius.
However, you should not think that any “Litol” is the same. There are multifunctional formulations labeled EP (Extreme Pressure), which contain extreme pressure additives based on sulfur and phosphorus. These are the materials that are needed for loaded components, such as steering rod joints and ends. Regular lubricant without EP additives can simply be squeezed out of the assembly under high load, leaving metal on metal.
⚠️ Caution: Do not apply lithium grease to parts that come into contact with copper (such as brake calipers), as a chemical reaction occurs that leads to corrosion and jamming of the mechanism.
Modern lithium complexes have improved properties and can withstand short-term heating up to 160-180 degrees. They are ideal for maintenance chassis, cardan shaft crosspieces (if there are no special caps) and door hinges. Their thick consistency prevents leakage, creating a reliable protective layer.
Copper greases for high temperature components
When it comes to the braking system, material requirements change dramatically. Here temperatures can reach 300-400 degrees and higher, which leads to coking and burnout of conventional lithium compounds. Copper grease (Copper Grease) was created specifically for such extreme conditions. It is based on micronized copper particles, which provide a stable coefficient of friction even when the oil base is completely burned out.
The main function of the copper composition is to prevent parts from sticking. When heated, the metal expands, and without a protective layer, threaded connections or caliper guides can “weld” together. Application Copper paste on the back of the brake pads, caliper pins and bolt threads ensures that the next time you change wheels you can easily dismantle the unit.
In addition, copper has excellent electrical conductivity and anti-corrosion properties. This makes it indispensable for processing contacts in conditions of high humidity and salt reagents. It is important to apply it in a thin layer, as excess material can lead to contamination of the brake discs and reduced braking efficiency.
Before applying copper grease, be sure to clean the surface with a wire brush to remove old rust and dirt, otherwise the protective layer will not apply evenly.
Graphite compounds and corrosion protection
Graphite lubricants are a special class of materials where graphite is the thickener and active component. This substance has a unique layered structure, which provides a “sliding” effect even under enormous pressure. Graphite grease (often found under the name USsA) is characterized by increased stickiness and adhesion to metal.
The main areas of application are springs for trucks and cars, as well as open gear drives. Graphite fills microcracks in the metal and creates a barrier that prevents moisture penetration. Unlike lithium analogues, graphite compounds work better under conditions of shock loads and vibration without splashing.
However, graphite also has its limitations. It conducts electricity, so it should absolutely not be used in electrical circuits where insulation is required. Also, graphite dust can pollute the surrounding area, so it should be applied carefully, avoiding contact with the paintwork of the body.
| Parameter | Lithium grease | Copper paste | Graphite grease |
|---|---|---|---|
| Temperature limit | up to +120°C | up to +1100°C | up to +700°C |
| Moisture resistance | High | Average | Low |
| Electrical conductivity | Dielectric | Explorer | Explorer |
| Main Application | Bearings, hinges | Brakes, exhaust | Springs, open pairs |
Silicone lubricants and rubber care
While metal parts require protection from friction, rubber and plastic parts need to maintain their elasticity. Silicone grease (Silicone Spray) is chemically inert and does not react with most polymers. It creates a thin hydrophobic film that repels water and prevents the rubber from drying out.
The main purpose of silicone is to care for the seals of doors, windows and hatches. Regular processing silicone spray prevents rubber bands from freezing in winter and eliminates squeaks. Unlike petroleum products, silicone does not corrode rubber or cause it to swell, which often happens when using the wrong lubricants.
Silicone compounds are also widely used to lubricate plastic guides and window lift mechanisms. They do not collect dust as aggressively as their oil counterparts, and retain their properties at low temperatures without freezing into an icy crust.
Why can’t you lubricate rubber seals with grease?
Solid oil and other petroleum lubricants contain aggressive components that over time destroy the rubber structure. It loses elasticity, cracks and ceases to seal the interior from water and noise.
Specialized lubricants for CV joints
Constant velocity joints (CV joints or “grenades”) operate under extreme conditions: high loads, large rotation angles and significant pressure. Conventional lubricants cannot cope here - they are squeezed out of the working area, leaving the metal rollers without protection. For these purposes, special molybdenum lubricants (based on molybdenum disulfide MoS2).
Molybdenum has a unique property: at high pressure it forms a strong film on the metal surface, which prevents direct contact of rubbing pairs. Visually, such lubricants usually have a dark gray or black color. It is important to use only compounds specifically designed for CV joints, as they contain a package of additives that protect against shock loads.
There is a misconception that the more molybdenum, the better. In fact, excess particulate matter can act as an abrasive under certain conditions. Therefore, it is important to choose products from trusted brands that follow the exact recipe. Changing the CV joint lubricant is a critical procedure whenever the drive shaft is removed.
☑️ Checking the condition of the lubrication in the CV joint
Mistakes when choosing and using lubricants
One of the most common mistakes is mixing different types of lubricants. The chemical bases may be incompatible: when mixing lithium and calcium thickeners, separation of the mass may occur, it will become liquid or, conversely, harden into a lump. Compatibility is a key factor in maintenance.
Cleanliness of surfaces before application is also often ignored. Spreading new lubricant on top of the old one, which contains wear products and dirt, negates the entire effect of maintenance. It is necessary to carefully remove old residues with solvent or gasoline before laying new material.
⚠️ Warning: Do not use WD-40 or similar “penetrating fluids” as a long-term lubricant. They are designed to clean and remove rust, but do not create a protective layer and evaporate quickly, leaving the parts dry.
Another mistake is using graphite or copper lubricants in electrical contacts where a dielectric is required, or vice versa. Always read the instructions on the bottle or can. Modern synthetic polyurea lubricants may be more universal, but they are much more expensive and are not required everywhere.
The correct choice of lubricant does not depend on the price, but on the compliance of its characteristics with the operating conditions of a particular unit: temperature, load and material of the parts.
Frequently asked questions (FAQ)
Is it possible to lubricate hub bearings with regular Litol?
You can use regular Litol-24, but only as a temporary solution or for low-speed components. For wheel bearings of modern cars that operate at high speeds and temperatures, it is better to use special high-temperature greases with a lithium complex or polyurea. Litol can quickly lose its properties and leak.
How to lubricate the caliper guides if there is no copper grease?
For the caliper guides (pins), it is critical to use a special synthetic PAG (polyalkylene glycol) based lubricant that is compatible with rubber boots. Copper grease is applied only to metal surfaces (back of pads, brackets), but not to rubber seals, as copper can cause their degradation.
Why do door hinges squeak after lubrication?
The creaking may persist if the lubricant has not penetrated deep into the gap between the axle and the hinge bushing, but remains only on the outside. It is often necessary to open and close the door several times to distribute the material. The reason may also be the use of too thick grease in severe frost or, conversely, old grease that has dried out inside, which must first be washed with a solvent.
Which lubricant is best for winter?
For winter conditions, synthetic lubricants based on lithium complex or polyurea with a low pour point are best suited. Silicone lubricants also perform well in cold weather, maintaining the elasticity of the rubber. It is important to avoid sodium soap-based formulations, which can harden at low temperatures.