MAMMOTH PETROLEUM
778-370-3330
Phillips 66® Transmission Oil SAE 90 is a high-quality, straight-grade mineral lubricant specifically engineered for use in heavy-duty manual transmissions, transfer cases, and final drives that require a non-EP (Extreme Pressure) oil. This specialized formulation is designed for gearboxes where sulfur-phosphorus additives—commonly found in standard gear oils—could lead to chemical corrosion of yellow-metal components. By utilizing premium, high-viscosity-index mineral base stocks, it provides a robust lubricating film that maintains its integrity under heavy loads and high operating temperatures. It is the ideal choice for legacy commercial vehicles and industrial equipment where a simple, reliable API GL-1 lubricant is specified to ensure mechanical longevity and internal cleanliness.
PRODUCT RESOURCES
PERFORMANCE
Non-Corrosive Formula: Engineered without active sulfur or phosphorus, making it entirely safe for brass, bronze, and copper internal parts.
Thermal Stability: Resists the thickening and oxidation that occurs during long-duration, high-torque operations in older drivetrains.
Anti-Foam Chemistry: Maintains a stable, non-compressible lubricating film to ensure consistent cooling and protection of top-shaft bearings.
PROTECTION
Yellow-Metal Defense: Specifically formulated to prevent the chemical pitting and etching of synchronizers and bushings in legacy gearboxes.
Wear Shield: Provides a thick, high-tenacity oil film that prevents metal-to-metal contact and scuffing on gear teeth.
Rust Inhibition: Contains a robust additive package that protects internal steel components from moisture-related rust during periods of downtime.
UPTIME
Component Longevity: Prevents the premature failure of bronze bushings and brass shift forks caused by improper lubricant selection.
System Cleanliness: High-detergency mineral base prevents the accumulation of sludge and carbon deposits that can impede oil flow.
Operational Reliability: Delivers consistent shifting performance in older manual units designed for high-viscosity straight-grade oils.
COMPOSITION
RESISTANCE
PROTECTION
FEATURES & BENEFITS
API GL-1 Compliance: Formulated strictly for applications where "Extreme Pressure" additives are forbidden or unnecessary.
Seal Compatibility: Specifically engineered to be compatible with the legacy elastomeric seals found in older vocational equipment.
High Flash Point: Reduces the risk of oil vaporization and fire in high-temperature heavy-duty industrial environments.
Versatile Utility: Suitable for use in a wide range of manual gearboxes, transfer cases, and low-speed industrial gear drives.
Proven Durability: Utilizes time-tested mineral technology to provide reliable protection in high-hour commercial drivetrains.
APPLICATIONS
Heavy-duty manual transmissions in older commercial trucks requiring an API GL-1 SAE 90 oil.
Transfer cases and steering gear boxes in vintage vocational and off-road equipment.
Industrial gear drives and farm machinery requiring a non-EP, straight mineral gear lubricant.
Select spiral-bevel and worm gear sets where high-friction EP additives would cause excessive wear or corrosion.
Licenses & Approvals:
API Service GL-1
Recommended for use in applications where an SAE 90 mineral oil is specified by the OEM.
MAMMOTH TECHNICAL TIP:
In the world of heavy-duty maintenance, the "SAE 90" designation is often misunderstood. While it shares a viscosity grade with common 80W-90 gear oils, the chemistry is fundamentally different. This is an API GL-1 oil, meaning it lacks the "Active Sulfur" needed for hypoid gears but is mandatory for older manual boxes with brass synchronizer rings. If you use a modern GL-5 gear oil in a unit requiring Transmission Oil SAE 90, the sulfur will chemically "peel" layers of copper off the synchronizers, leading to a golden-glitter appearance in the drain oil and eventual shifting failure. For older Spicer or Fuller units that specifically call for mineral gear oil, this SAE 90 is the exact specification to keep that brass alive.