What Is Grease?
Grease is a type of automotive lubricant that is used to protect car parts against friction. It is responsible for the lubrication of moving engine parts.
Grease is thicker in consistency compared to other automotive lubricants like motor oil and well-suited for certain automotive applications like lubricating the wheel bearing, chassis, and universal joints.
Automotive grease comprises three main components.
They are:
- Base oil
- Thickener
- Additives
The base oil is composed of mineral or synthetic oil, and the thickener is made up of a metallic soap that may contain lithium, poly-urea, calcium, sodium, aluminium, or clay.
Meanwhile, oil additives make it possible for automotive grease to perform various functions other than lubrication.
What is the use of automotive grease?
Aside from being a lube, automotive grease is also useful for protecting the engine parts and extending their working life.
The thickener enhances its consistency and texture, making it very long-lasting and efficient.
It’s specifically recommended for high-pressure and heavy-duty applications since — unlike engine oil — it retains all of its properties under pressure and doesn’t lose shape.
Automotive grease is also useful in:
- Keeping out water and protection against rust and corrosion
- Maintaining a clean engine, free of dust and dirt
- Providing long-lasting resistance against friction
- Reducing the noise caused by the engine
- Reducing wear
In addition to these, certain greases are better suited for some jobs than others.
Types of grease
5 Types Of Automotive Greases
Automotive greases are made up of different kinds of oil additives that serve many purposes. So, it’s important to choose the right lubricating grease to achieve the results that you want.
Generally, grease is categorized into five different types.
They are:
1. General Purpose Grease
General-purpose grease (also known as GP grease) is formulated to serve various purposes, including most industrial and domestic uses. It consists of base oil with a medium viscosity index. It provides decent water and dirt protection but isn’t very long-lasting.
General-purpose grease is popularly used as a lube for ball joint parts, bearings, cables, gears, and hinges.
2. Molybdenum (Moly) Grease
This type of synthetic grease is made up of an oil additive called molybdenum disulfide. It’s used as a lube for heavy-duty and high-pressure equipment, including CV joints, ball joint parts, and steering linkages.
Moly grease provides excellent lubrication and protection against friction and is highly recommended for disc brake wheel bearings. It can also work as chassis grease.
Due to its high resistance to friction, moly grease isn’t recommended for fast-moving metal parts like roller bearings since this grease would slow them down.
3. Lithium Grease
Lithium grease is a type of multi-purpose white grease, also known as wheel bearing grease. It consists of lithium soap, which is a non-detergent soap.
As a lubricant, lithium grease is very stable and has high resistance to water and corrosion on metal.
White lithium grease is very convenient since you can keep track of how much grease you’re applying. You may also use white grease to lube car door hinges. Since it’s a multi purpose grease, you may also use it for other household purposes.
4. Calcium Sulfonate
Calcium sulfonate is another kind of multi purpose grease that is highly resistant to water. It’s also known as marine grease, and helps in the lubrication and protection of marine machinery.
The high water resistance in marine grease makes it a great lubricant for car parts that frequently contact moisture — protecting them from rust and corrosion. This includes wheel bearing, chassis, ball joint parts, and universal joints.
Because of this, calcium sulfonate grease is also sometimes known as chassis grease.
Note: Marine grease is not compatible with white lithium grease. Do not apply it if you previously lubricated your equipment with lithium complex or lithium grease. Mixing incompatible lubricants may result in the separation of base oil and additives.
5. Polyurea Grease
Polyurea is a multi purpose grease that is well suited for long-service use. It has a fairly thick consistency and is ideal for “sealed-for-life” bearings and high temperatures wheel bearings.
Greases containing this additive are characteristically long-staying and are very stable under high temperatures and pressure. They are also great at absorbing engine noise and have good water-resistant qualities.
Apart from these, there are also specialty greases formulated for special applications.
Things to consider in choosing grease
Automotive greases have several qualities that make them ideal for many car parts.
But the type of grease you choose will depend on the following factors:
1. Oil Composition
When choosing the right grease, consider the kind of additives and base oil it has.
Will you need additives with corrosion inhibitors?
Or do you need a base oil that has a strong adhesive property?
For example, if you need protection against friction and high-pressure automotive applications, go with greases made of synthetic oil as a base.
2. Grease Consistency
Each type of grease is assigned an NLGI grade, ranging from the number 000 to 6.
It ranges from grease that is very soft and fluid (000) to grease that is very hard and firm (6).
Choose your grease based on what consistency you need.
For example, wheel bearings will require a moderately fluid NLGI grade 2 grease, whereas the gearbox components will need a fluid NLGI grade 00 grease.
3. Viscosity
The viscosity of grease characterizes its ability to remain stable under high temperatures and pressures. The higher the viscosity of the grease, the better protection against friction.
On the other hand, low viscosity greases are ideal for high-speed engine parts.
4. Pressure And Temperature Performance
While selecting a lubricating grease for your passenger cars, make sure you keep the nature of its application in mind.
Look for an automotive grease with extreme pressure and high-temperature resistant additives for a stable grease that doesn’t bleed under high performance.
For example, a moly grease suitable for heavy-duty performance won’t be the best for a high-temp wheel bearing application. In this case, you’d need lithium grease.
5. Grease Compatibility
When changing to a new lubricating grease, you need to make sure it’s compatible with your old grease.
It’s impossible to clean out almost all of the old grease before applying a new one, and incompatible greases often react and harm the engine parts when forced into contact.
Avoid mixing greases that do not work with each other.
For example, poly-urea grease is incompatible with white lithium grease (both simple and lithium complex grease). You may also want to refer to the vehicle manual if it recommends any speciality grease for your engine.