Motor Oil Basics Lubricate and cool – Generally,when people talk about 'motor oil,' they are talking about the oil that goes into the crankcase, a special oil reservoir, in a four-cycle engine, like the engine in your car. Motor oil lubricates the engine of a vehicle or piece of equipment and cools a significant portion of the engine. While the engine is at rest, the motor oil rests in the crankcase, a pan bolted to the bottom of the engine block. When the engine starts, the oil pump feeds oil from the pan to the oil distribution system, a network of passages, tubes, grooves and holes leading to the engine bearings and other surfaces that receive a large volume of pressurized oil for lubrication. Other parts receive oil through splash or spray. For example, the overhead valve system receives a carefully controlled quantity of non-pressurized oil for lubrication.
Other functions – In addition to lubricating and cooling engine parts, motor oil must allow easy engine starting, protect the engine from corrosion and oxidation, keep the engine clean, form a tight seal between piston rings and cylinder walls, and help the engine use fuel efficiently.
Diesel engines require protection against the corrosion caused by a combination of their extremely high operating temperature and acidic products introduced into the engine by diesel fuel and products of oil breakdown. Diesel oils provide protection against corrosion through detergent-alkalinity additives, which give the oil its Total Base Number (TBN). Oils with high TBN neutralize acids over a longer period than oils with low TBN do. In fact, in programs of used oil analysis, used by fleets to reduce their maintenance costs, an oil's fitness for ongoing service is determined largely by its TBN.
2-Cycle Oil Basics
Two-cycle oil, used to lubricate two-cycle gasoline-fueled engines, mixes with the engine’s gasoline and the mixture is burned for energy. Some engines are designed to use a gasoline-oil mixture that must be made before introducing the mixture into the engine’s fuel tank; the oil used in these engines is called pre-mix oil. Some engines are designed for introduction of oil and gasoline into separate compartments with the oil injected into the combustion chamber or into the fuel system; the oil used in these engines is called injector oil.
Due to their light weight, two-cycle gasoline-fueled engines find application in outboard marine engines,motorcycles, ATVs, chainsaws, portable equipment and snowmobiles. Two-cycle engines rev high, so they wear fast. If you were to leave a two-cycle engine and a four-cycle engine of the same displacement running for an hour, the four-cycle engine would complete about 100,000 revolutions while the two-cycle would complete 300,000 to 400,000. Each revolution causes wear.
Suspension Fluid Basics
Suspension/fork fluids lubricate and protect the inner walls of shocks and forks in motocross and cruiser motorcycles, snowmobiles, ATVs and other high performance and recreational vehicles. They may contain friction modifiers to reduce frictional energy loss and antiwear agents to protect against premature wear and scuffing. Suspension/fork fluids also prevent fade and allow for smooth rebounds.
Chain Case Lube Basics
Chain case lubricants lubricate and protect enclosed chains, such as those on snowmobiles, ATVs, and other equipment. Chain case lubricants may contain extreme pressure additives for added wear protection. Chain case lubricants may also repel water and inhibit rust, oxidation and foam. Synthetic chain case lubricants allow easy cold temperature equipment startup, performance and protection.
Transmission Fluid Basics
Automatic transmission fluid (ATF) is used in passenger car and commercial vehicle automatic transmissions; offhighway construction, agricultural and mining equipment powershift transmissions; and in some industrial applications which require hydraulic fluids with extreme high or low temperature performance capabilities. Almost half of all ATF goes to the automotive transmission market.
A vehicle’s transmission is the first link in transmitting the engine’s power to the wheels, allowing the vehicle to begin moving from a standstill,move forward or in reverse,move at various speeds, or to allow the engine to continue running while the vehicle is stopped. An automatic transmission uses a hydraulic coupling between the engine and the gears. The hydraulic coupling, rather than the driver, does the work of selecting gears.
Automatic transmission fluid serves as a hydraulic fluid, transmitting power from the engine to the gears, and serves as a lubricant, cooling the torque converter assembly and lubricating the transmission gears. ATF is perhaps the most complex lubricant in existence.
Because of the extremely narrow passageways in their electronic shift selectors, automatic transmissions are extremely sensitive to fluid viscosity and do not function properly when cold thickens ATF excessively.
Extremely high operating temperatures make automatic transmissions tend to thermally and oxidatively degrade ATF rapidly.
Special frictional requirements of lockup torque converters and continuously slipping converter clutches make automatic transmissions are vulnerable to shudder, a condition that develops after roughly 30,000 miles use and causes severe vehicle handling difficulties.
Gear Lube Basics
Gear lubes lubricate, cool and protect geared systems. They also carry wear debris away from contact zones between gears and muffle the sound of geared system operation. Gear lubricants are used in differential gears and some standard (non-automatic) transmission gears in equipment,commercial vehicles and passenger vehicles,with the majority of gear lubes going to the commercial vehicle market. Some industrial machinery gears are also lubricated with gear lubes. The transmission carries the engine’s power to the driveshaft and allows selection of appropriate gears to start the vehicle moving from a standstill,move up to road speed, pull a heavy load or move in reverse. The differential carries the power from the driveshaft to the wheels. Because the driveshaft and the wheels rotate at 90° angles to one another, the differential contains gears to change the direction of the rotational power it receives. The severe angle of differential gears does not allow them to maintain a full lubricating film to separate mating surfaces. Additionally, the severe angles of their contact tend to concentrate load on a very small area of the gear face. Due to the lack of full film separation and to the concentrated points of load, differential gears are protected from excessive wear by extreme pressure agents, additives that form a protective shield over surfaces.
Vehicle power and load generate heat in the transmission and differential. Commercial vehicle differential temperatures have risen dramatically in recent years, due to increased engine output, increased vehicle loads and aerodynamic body styling. Higher temperatures increase the occurrence of thermal degradation of the lubricant, which leads to sludge, deposits and seal damage.
Thermally stable gear lubes keep parts free of sludge and deposits, and protect seals, even when the gear lubes are subjected to sustained high temperature service.
Gear lubes can lose their extreme pressure performance when they are subjected to sustained thermal stress. Loss of extreme pressure performance allows metal to metal contact in susceptible areas, causing wear rates to accelerate.
Thermally durable gear lubes protect surfaces from wear, even when the gear lubes are subjected to sustained high temperature service.
Grease Basics
Grease is the lubricant of choice in applications where liquid lubricants cannot stay in place. Such applications include wheels and auto chassis. Because it is a semi-solid lubricant, grease stays in place; prevents debris from entering greased systems; and provides structure for the suspension of solid lubricating materials, such as molybdenum. The use of grease reduces lubricant loss and relubrication frequency.
High load applications, such as those in heavy equipment bearings, benefit from the addition of solid lubricant additives, such as molybdenum,which 'plateout' on metal surfaces and protect them from lubricating film breakdown in extreme load conditions.
Many applications subject greases to water. To provide adequate protection against wear, greases must resist washing out. Rust protection is important, too.
The automatic greasing systems used to distribute grease in industrial machinery require greases with good cold temperature characteristics for dependable feeding into the automatic grease system.
Compressor Oil Basics
Compressed air is a source of energy used for powering tools, inflating pneumatic tires and spraying liquids. Compressor oils lubricate compressor components, such as bearings,pistons, rings and valves.
The bicycle pump is a simple compressor: as the cyclist pulls the pump handle up, air is drawn past the leather cup “piston” into the cylinder of the pump and held at normal pressure. When the cyclist pushes the handle down, the resistance of the air in the cylinder spreads the leather cup, enabling it to compress the air in the cylinder until the air achieves sufficient pressure to pass through the non-return valve into the bicycle tire.
Because compressors often generate intense heat, small, high-pressure compressor oil leaks create an explosion and fire hazard.
Due to their exposure to ambient air, which always contains moisture, compressors accumulate water in the compressor oil.
Compressors can work air and water into fluids, creating foam,which impedes the oil’s ability to protect surfaces.
