Your differential is probably the most neglected part of your vehicle's drivetrain. Yet it's use can generate heat upwards to 200 degrees F. When is the last time you changed your fluid?

Many truck and SUV owners personalize their vehicles with aftermarket products such as lift kits, tires and rims, custom grills, paint, wheel well flairs and engine upgrades. While these upgrades and accessories can increase engine performance and add plenty of visual
appeal, they do nothing for extending drivetrain life.

Most people perform proper engine maintenance and change their engine oil on a regular basis, but according to one quick lube business, only about 2 percent of it's customers purchase differential gear lube changes.Sometimes this out of sight, out of mind differential neglect results in costly gear failure, leaving the motorist stranded on the highway.

There are two basic ways to change differential gear lube. The old fluid may be drained or suctioned out and the differential refilled with new gear lube, or the differential cover may be removed to allow more of the old gear lube to drain out and allow access to the magnet inside the differential. Unlike engines, differentials are not equipped with filters. Instead, magnets that are open to
the entire gear lube sump are used to catch some of the metal wear particles. When changing differential fluid, the magnet should be cleaned to ensure the new gear lube does not become contaminated.

After draining the old fluid and cleaning the magnet, the differential cover should be re-installed and the differential filled with the correct viscosity grade of AMSOIL SEVERE GEAR® Synthetic Gear Lube. The use of cleaning solvents is not recommended. Initial differential oil changes are recommended by some manufacturers after the first 500 to 3,000 miles.

Even when vehicle manufacturers do not specify to change the factory-fill gear lube to remove wear particles, it is a good practice to do so. For optimum gear and bearing life, AMSOIL recommends the factory-fill differential gear lube be changed no later than the first 5,000 miles with new or rebuilt gears, followed by 50,000-mile drain intervals in severe service or 100,000-mile drain intervals in normal service when using AMSOIL synthetic gear lubes.

AMSOIL recommends any one of three SEVERE GEAR viscosity grades, 75W-90, 75W-110 or 75W-140, for turbo diesel or 4x4 trucks, SUV’s and automobiles. SEVERE GEAR 75W-90 (SVG) replaces competitive 75W-90 and 80W-90 gear lubricants and delivers the optimum fuel efficiency and cold temperature performance of all the SEVERE GEAR gear lubes. SEVERE GEAR 75W-110 (SVT) replaces competitive 75W-110, 75W-90 and 80W-90 gear lubricants and delivers increased fluid film wear protection over lighter viscosity fluids and better fuel efficiency than 75W-140 gear lubes. SEVERE GEAR 75W-140 (SVO) replaces competitive 75W-140, 80W-140 and 85W-140 gear lubes in applications where these viscosities are recommended
by equipment manufacturers.

Magnets to attract metal filings

Iron wear particles

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Various gear lubes

Whitepaper: Gear lube

Amsoil Introduces New Synthetic 7W-110 Severe Gear Lube

Vehicles have recently seen tremendous gains in both
horsepower and towing limits. In fact, horsepower has
increased by as much as 93 percent in turbo diesel
trucks and vehicle towing limits have increased from
7,500 to 18,000 lbs. in recent years, causing differentials
to run hotter than ever. At the same time, vehicle
manufacturers have been under pressure to meet government-mandated fuel efficiency requirements.

The Society of Automotive Engineers (SAE) sets viscosity parameters for gear lubes in its SAE J-306 document. Until recently, the viscosity range for SAE 90
gear lubes was very broad, ranging from 13.5 cSt to <24
cSt. Because correct gear lube viscosity is critical to
proper lubrication, gear manufacturers have been concerned the gear lubes on the low end of the SAE 90
scale may not provide adequate protection. At 16.4
cSt, AMSOIL SEVERE GEAR ® 75W-90 Synthetic Gear Lube (SVG) is formulated well within the SAE 90 viscosity range and has always ensured superior viscosity
protection in systems specifying an SAE 90 gear lubricant.

In order to ensure adequate gear protection, some manufacturers, including Ford, recommend an SAE 140 gear lubricant. However, the use of an SAE 140 gear lubricant increases viscosity drag and reduces the efficiency of the gear system, resulting in increased
energy consumption and decreased fuel economy.

broad viscosity range of SAE 90. With a viscosity range
of between 18.5 cSt and <24 cSt, the new SAE 110
classification is midway between SAE 90 and SAE 140.
This new classification assures gear manufacturers of
sufficient viscosity protection, as well as improved efficiency and fuel economy over SAE 140 gear lubricants. A similar viscosity range break-up occurred with the SAE 140 classification, with the new SAE 190 classification splitting the range between SAE 140 and SAE 250. SAE 190 and 250 gear lubricants are thick viscosity oils for special applications.

Although no manufacturers currently specifically recommend SAE 110 viscosity gear lubes, they fulfill the requirements of the previous SAE 90 classification and may be used wherever SAE 90 is recommended. New 75W-110 SEVERE GEAR Synthetic Gear Lube (SVT) provides superior protection for elevated operating temperatures without sacrificing fuel efficiency. It is formulated for use with limited slip clutches and is ideal for turbo diesel pick-up trucks, vehicles used for towing and hauling and other vehicles subject to severe service operating conditions, including heavy equipment, construction vehicles, emergency vehicles, street rods and 4x4 vehicles.

It is recommended in applications specifying API GL-5 or MT-1 and MIL-PRF-2105E.
AMSOIL 75W-110 SEVERE GEAR Synthetic Gear
Lube joins 75W-90 (SVG) and 75W-140 (SVO) SEVERE GEAR Synthetic Gear Lubes as premium grade lubricants specifically engineered for maximum performance in severe duty applications. SEVERE GEAR Synthetic Gear Lubes feature an exclusive blend of high viscosity, shear stable synthetic base stocks and an extra treatment of high-performance additives, maintaining viscosity for long-lasting protection against metal-to-metal contact in both hot and cold temperature
extremes.

The proprietary AMSOIL additives form an
iron-sulfide barrier coating on gear surfaces, providing the ultimate line of defense against wear, pitting and scoring. SEVERE GEAR Synthetic Gear Lubes help prevent “thermal runaway,” a phenomenon caused by a lubricant’s inability to control friction and increased heat under high stress conditions. By controlling thermal runaway, SEVERE GEAR Synthetic Gear Lubes inhibit rapid lubricant degradation and component damage.
AMSOIL SEVERE GEAR Synthetic Gear Lubes provide extended drain intervals of 100,000 miles in normal service or 50,000 miles in
severe service, or longer if specified by the owners
manual.

AMSOIL SEVERE GEAR Synthetic Gear Lubes are recommended for use in differentials, manual transmissions and other gear applications requiring any of the following specifications: API GL-5, MT-1, MIL-PRF-2105E, Dana SHAES 234 (formerly Eaton PS-037), Mack GO-J or the differential (hypoid) gear lube specifications from GM, DaimlerChrysler, Ford and all other domestic and foreign vehicle manufacturers. SEVERE GEAR Synthetic Gear Lubes may also be used in axles where an API GL-4 lubricant is recommended.

Specific recommendations for SEVERE GEAR Synthetic Gear Lubes are as follows:
SEVERE GEAR 75W-90 (SVG) replaces competitive
75W-90 and 80W-90 gear lubricants. It delivers the
best fuel efficiency and cold temperature performance
in the SEVERE GEAR line. SEVERE GEAR 75W-110 (SVT) replaces competitive 75W-110, 75W-90 and 80W-90 gear lubricants. It delivers better viscosity
protection than SEVERE GEAR 75W-90 and better fuel efficiency than SEVERE GEAR 75W-140. SEVERE GEAR 75W-140 (SVO) replaces competitive 75W-140, 80W-140 and 85W-140 gear lubricants. It is recommended wherever these viscosities are required by equipment manufacturers.