AMSOIL SEVERE GEAR® SAE 250 100% SYNTHETIC GEAR LUBE

AMSOIL SEVERE GEAR SAE 250 100% Synthetic Gear Lube is a purpose-built, extreme-pressure racing gear lubricant designed to protect differentials in the most punishing motorsport and off-road conditions. If your rig sees competition-level abuse, shock loading, or steep angles that would sling conventional gear lube right off the ring and pinion, this is the product that stays put.

Off-road race trucks, rock racers, rockcrawlers, pulling tractors, funny cars and dragsters all share one thing in common: they generate forces that destroy differentials running inadequate lubricant. High G-forces during hard cornering or launches can centrifugally sling gear lube away from the contact surfaces where it's needed most. Ring and pinion gears run at steep angles, like those found in high-pinion axle configurations or during extreme approach and departure angles in rockcrawling, lose oil film coverage when the lubricant can't cling to the gear teeth. The result is metal-to-metal contact, pitting, scoring and premature failure of components that cost thousands to rebuild.

EXTREME FILM STRENGTH FOR MAXIMUM WEAR PROTECTION
SEVERE GEAR SAE 250 combines an extra-heavy additive package with shear-stable, heavy synthetic base oils to deliver a thick, resilient lubricant film between gear surfaces. In Falex Procedure B testing per ASTM D3233, this gear lube withstands a failure load of 3,250 lbf. Its proprietary extreme-pressure additives form an iron-sulfide barrier directly on gear surfaces, providing a secondary line of defense against wear even when the fluid film is momentarily compromised under extreme load. Four-Ball Wear Test results per ASTM D4172 show a wear scar of just 0.40 mm, confirming the formulation's ability to cushion metal surfaces and absorb impact from moving parts under high contact pressure.

RESISTS SLING-OFF AND CLINGS TO GEARS AT STEEP ANGLES
This is where SAE 250 earns its place in serious competition builds. The formulation is specifically engineered for high-horsepower, high-torque conditions where centrifugal force throws lighter gear lubes off the gear teeth entirely. SEVERE GEAR SAE 250 clings tenaciously to gears and bearings during shock loading, high-G launches, aggressive cornering, and when the vehicle is at steep operating angles. For rockcrawlers running high-pinion Dana axles at extreme articulation, or a funny car hammering the rear end at launch, this gear lube maintains coverage where it matters.

EXCELLENT FLUIDITY DESPITE HIGH VISCOSITY
Despite a kinematic viscosity of 474.8 cSt at 40°C and 46.6 cSt at 100°C, SEVERE GEAR SAE 250 flows far better than its viscosity grade suggests. Because it's built entirely from synthetic base oils, it does not contain the wax molecules found in conventional gear lubes that solidify in cooler temperatures. The pour point reaches -25°C (-13°F), which is remarkably low for a lubricant this heavy. This means the gear lube reaches gears and bearings quickly at startup rather than sitting in the sump waiting to warm up. That superior fluidity also reduces viscous drag and parasitic energy loss, helping put maximum power to the ground rather than wasting it churning thick oil.

PROMOTES COOLER OPERATING TEMPERATURES
The synthetic base oil construction and high viscosity index of 154 help SEVERE GEAR SAE 250 maintain consistent film thickness across a wide temperature range without excessive thickening at lower temperatures. Reduced internal fluid friction translates directly to lower differential operating temperatures, which extends both lubricant life and component life. The flash point of 234°C (453°F) provides a wide thermal safety margin even in differentials generating significant heat under sustained heavy loads.

SPECIFICATIONS AND COMPATIBILITY
SEVERE GEAR SAE 250 is formulated for use in hypoid gear differentials and other applications requiring a high-viscosity API GL-5 gear lubricant. Target applications include off-road race trucks, rock racers and rockcrawlers, competition pulling tractors, funny cars, dragsters, and heavy-duty trucks and equipment where increased lubricant film thickness is necessary. For limited-slip differentials, add AMSOIL Slip Lock limited-slip additive. SEVERE GEAR is compatible with both synthetic and conventional automotive gear oils, though mixing with other oils will reduce oil life and performance. Aftermarket oil additives not specified by AMSOIL are not recommended.

SERVICE LIFE
SEVERE GEAR SAE 250 is intended for severe racing and competition applications where extended drain intervals are not the priority. Change intervals should be determined by operating conditions. For those wanting to extend beyond standard racing intervals, oil analysis is the recommended path to establish appropriate drain timing for your specific application.