Types of Automotive Lubricants
A quick trip to an auto-parts store reveals several different types of lubricants. Each one has a specific purpose and use. Choosing the correct type of automotive lubricant can extend the life of an expensive part, while choosing the wrong lubricant will destroy it quickly. A little basic lubrication knowledge can save large amounts of money in the long run.
Motor Oil: Motor oil is the most common type of automotive oil used. Many vehicle manufactures recommend replacing motor oil every 3,000 miles. Motor oil typically contains additives to prevent break down, corrosion and reduce foaming. Motor comes in many different viscosity ratings. Viscosity of an oil is its thickness. It measures the oil's internal resistance to flow, or friction. The smaller the viscosity number, the thinner the oil is and the easier it flows. Most automobile manufactures recommend a multi-grade motor oil like 5W-30. The purpose of a multi-grade oil is to have a certain viscosity rating when the oil is cold and a separate, but limited, viscosity rating when the oil heats. The "W" stands for winter, not weight.
Gear Oil: Gear oil is used when a high temperature lubrication is needed. Commonly used in a vehicle's differential and manual transmission, gear oil typically has a viscosity rating above 75. A common gear oil is 75W-90. Gear oil has a distinctive smell.
Transmission Fluid: Transmission fluid is a slick lubricant that serves many purposes. It lubricates all moving parts in the transmission, cools the transmission, prevents corrosion and conditions the seals. Transmission fluid is brightly colored to help detect leaks. Transmission fluid should be checked with the vehicle running on a flat and level surface. The dipstick usually is located toward the rear of the engine compartment. Transmission fluid is commonly used in a four-wheel drive's transfer case.
Wheel Bearing and Chassis Grease: This is the most commonly used automotive grease. It is found in the suspension and steering joints. To prevent premature wear, suspension parts should be lubricated regularly and when ever squeaks and groans are heard. Parts that need lubrication have grease fittings. This type of grease commonly comes in a tube that fits in a grease gun. The grease gun will attach to the grease fittings and when the trigger is squeezed grease will enter the fitting. This is not a high-temperature grease and will not work on the wheel bearings of a vehicle with disc brakes.
High-temperature Wheel Bearing Grease: This grease is designed for high-temperature applications. Vehicles with disc brakes use this type of grease in its wheel bearings. It contains an additive that remains slippery even when the grease dries.
White Grease: White grease is a water proof grease designed to work in metal to metal applications where water penetration is a problem. White grease will not wash away or dilute in water. White grease typically has a large temperature rating.
Electronic Grease: Used on electrical connections where the heat must not build up, electronic grease is sometimes called heat-sink grease. This grease will not conduct electricity.
Penetration Lubricants: This type of lubricant typically comes in an aerosol can. It is used to loosen and lubricate seized, rusted and corroded nuts and bolts. This lubricant works best when it is allowed to soak in. After letting it soak in, use a wire brush to clean the threads then reapply the penetrating oil.
Graphite: Graphite should be used to lubricate parts that should not be exposed to oils. A common place to use graphite would be in door locks.
Always follow the vehicle manufacturer's recommend lubrications. When in doubt consult a service manual or ask the clerk at an automotive parts store. The lubrication's brand name does not really mater. What does mater is the type and grade of lubricant chosen for the application.