Motor Oil Info

AMSOIL Severe Gear, Synthetic Gear Lubes demonstrate superior viscosity index and shear stability properties, and they are better-equipped to protect equipment against the devastating effects of thermal runaway. Severe Gear Synthetic Gear Lubes are blended with superior high (VI) viscosity improvers, shear stable synthetic base oils and an overtreatment of extreme pressure additives that effectively protect high-stress applications against friction, heat and wear.

Keeping equipment in top working order and ensure summer trips aren’t ruined by a broken-down vehicle. Specifically engineered for high-demand applications, including trailer towing, heavy hauling, 4×4 off-road driving, commercial use and racing.

Viscosity is the most important property of a lubricant in its defense against thermal runaway. Viscosity correlates to film thickness and film strength, which keep moving parts from contacting each other and creating increased friction, heat and wear. The higher the viscosity of a lubricant, the greater protection it provides. However, a lubricant which is too thick is detrimental because it consumes more energy and increases fuel consumption.

The original equipment manufacturer (OEM) determines which viscosity grade is optimum for the specific application. Many gear lubes are formulated with additives called viscosity index (VI) improvers. These additives broaden a lubricant’s operating temperature range and are used to ensure multi-grade viscosity performance for hot and cold temperatures.

The extreme pressures and temperatures generated by modern vehicles increase stress on gear lubricants and can lead to a serious condition known as thermal runaway. As temperatures in the differential climb upward, gear lubricants lose viscosity and load carrying capacity. When extreme loads break the lubricant film, metal-to-metal contact occurs, increasing friction and heat. This increased friction and heat, in turn, results in further viscosity loss, which further increases friction and heat.

As heat continues to spiral upward, viscosity continues to spiral downward. Thermal runaway is a vicious cycle that leads to irreparable equipment damage from extreme wear, and ultimately catastrophic gear and bearing failure.

Another summer season is underway, and with summer comes a wide variety of recreational activities such as fishing, boating, jet skiing and ATV and dirt bike riding. Many enthusiasts use trailers to tow their equipment, and in order to avoid any inconvenient and expensive breakdowns, it is crucial to ensure proper maintenance has been performed on the tow vehicle’s drivetrain. Nothing will ruin a weekend quicker than becoming stranded on the side of the road.

Severe duty activities such as towing heavy trailers, hauling heavy loads and off-roading place an increased level of stress on drivetrain components. Modern vehicles such as turbo diesel trucks and vehicles with V-10 engines boast more horsepower and torque than their predecessors, but differential designs have remained virtually unchanged through the years. Differentials today are subjected to severe duty service and encounter more stress and heat than was seen only a few years ago. So a gear lube fluid change is a great idea.

The differences in gear design create the need for significantly different lubrication designs, which is why manual transmissions sometimes use much different lubrication than differentials. For instance, hypoid gears normally seen in automotive differentials require API GL-5 concentration and performance of extreme pressure additives because of their spiral sliding action. For everyday driving API GL-5 performance and SAE 75W-90 viscosity is recommended. Heavy towing or hauling may require the use of API GL-5, 75W-140 viscosity since pressure between the ring and pinion gears are elevated.

As for manual transmission gearing, how they are set up and the service factor dictates the use of many different oils. OEMs sometimes recommend automatic transmission fluid such as MERCON or ATF+4, specialty lubes such as synchromesh fluids and API GL-4, 75w-90 viscosity gear lube. The difference in GL-4 and GL-5 is that GL-4 gear lubes have half the extreme pressure additives of GL-5. Because the gear types in manual transmissions do not necessitate the use of GL-5 gear lube, GL-4 is the correct recommendation called for by most OEM’s when gear lube is required.

When you think of oil, chances are that you are thinking about engine oil. This motor oil flows through your engine and provides lubrication to  mechanical components. However, there are others that are in many ways just as important.

One such oil is the gear oil. This mixture serves as a lubricant for the manual transmission, transfer case and differentials—many of the systems that are under constant stress. Because of this, gear oil has a very high viscosity compared to other forms of oil.

Did you know that Amsoil Marine Gear oil can still work in up to 10% of water.  This is very important because if you are out in the middle of the lake and a little bit of water creeps in, you are still protected.  With Amsoil you also protect your self against foam that might form.

When Foam does form it does make the gears wear because of the air in the lube.  That is something you want to avoid in your gear box. The more wear and tear the gears receives the less use it will allow. With more traditional lubes when mixed with water can form this foam like substance.  With Amsoil Marine gear lube tests have shown that it provides %50 more protection against water and helping your gears lasting longer.

The rotating motion of the gear sets also tends to churn the lubricant, resulting in foaming. If a gear lube foams, the load carrying capacity is significantly reduced because the air suspended within the oil is compressible. For example, when the gear teeth come into contact with each other any trapped air bubbles will compress, therefore reducing the thickness of the separating oil film. In turn, this reduction could lead to direct metal-to-metal contact between gear teeth and result in accelerated wear.

The gear lube must have the ability to dissipate this entrapped air, insuring sufficient lubricating film exists to protect the gears from contact wear. Much like engine oil the chemical compounds, or additives, added to drivetrain stocks either enhance existing properties or impart new ones.

Because many of the components found in the drivetrain consist of ferrous material, the lubricant is required to prevent rust and possible corrosion to other materials. Rust and corrosion problems are not nearly as prevalent in engines.

The many small and intricate components that make up gear sets found in the drivetrain can be quite noisy and may be subjected to shock loading. The viscosity and extreme pressure formulation of gear lubes quiets gears and dissipates shock loading.

Motor oil has to combat byproduct chemicals from gasoline or diesel ignition and should contain additives such as detergents and dispersants. Since an internal combustion engine has an oil pump and lubricates the bearings with a hydrodynamic film, the need for extreme pressure additives such as those used in gear lube does not exist in engines.

Engine oils and gear lubes both have anti-wear additives, they both must lubricate, cool and protect components, but gear lubes are placed under extreme amounts of pressure, creating a propensity for boundary lubrication. For example, differentials in cars and trucks have a ring and pinion hypoid gear set. A hypoid gear set can experience boundary lubrication, pressures and sliding action that can wipe most of the lubricant off the gears. To combat this extreme environment , extreme pressure additives are incorporated into the oil . AMSOIL uses an extra treat of extreme pressure additives in its gear lubes in order to reduce wear and extend the gear and bearing life.