75W-90 gear oil is a versatile oil with uses and ratings for transmissions, transfer cases, and differentials.

It is a high viscosity oil containing organosulfur compounds. An important fact: motor oil viscosity and gear oil viscosity use two different API ratings systems; the 75W-90 gear oil rating is not a thickness relative to motor oil weights. 

Most oils for manual transmissions and differentials also contain anti-wear and extreme pressure (EP) additives to cope with the sliding motion of hypoid bevel gears and, generally, the higher the rating the more EP that is present in the formulation. EP additives also contain phosphorous/sulfur compounds, which are corrosive to yellow metals such as the copper and brass used in bushings and syncros.

API Gear Oil Ratings

The API rating classification for gear oils include intended specifications, and the active ratings are GL-1, GL-4, GL-5, and MT-1. GL-4/GL-5 are the gear oils most suited to automotive uses. The designation of GL-4 is for gear oils intended for axles with spiral bevel or hypoid gears operating under varying conditions of speed and load. This oil may also be used in select transmissions and transaxles depending on manufacturers recommendations.

GL-5 denotes gear oils intended for hypoid gears in axles operating under various combinations of high speed/shock load and low speed/hi-torque conditions. Because of these differences it is important to be sure to refer to the correct specification for its intended use.


ENEOS Gear Oil 75W-90 GL-5 LSD is a fully synthetic product blended with superior quality base oils of Group IV PAO and Ester (also known as Group V base oil, primarily used for jet engines).

Because of these base oils and their ability to provide exceptional lubrication with built-in EP properties, less EP additive is needed, which is friendlier to yellow metals.

This high-quality formulation allows for use in bevel, spiral bevel, and hypoid gear type differentials, even under extreme conditions.  It is compatible with power dividers with synchromesh and limited slip differentials (LSD) requiring API GL-5. It also allows for a wider range of operating use than specified by its viscosity rating.

Our unique base oil formulation of ENEOS Gear Oil allows for use with the following viscosities: 75W, 75W-90, 80W, 80W-90, 85W, 85W-90, and 90.*

ENEOS GEAR OIL LSD [part #3094-300] is fully synthetic gear oil using the latest technology that ensures superior performance in every area required of differential gears, including LSD (Limited Slip Differential). The base oil and additive technology in ENEOS GEAR OIL LSD assures excellent protection of the gears against metal-to-metal contact under the most severe conditions, including shock loads. 

*Consult your vehicle’s owner’s manual for specific use.