Method of lubricating an automotive or industrial gear

An automotive or industrial gear oil comprising

• a. an oil of lubricating viscosity;
• b. a sulfurized olefin in an amount that provides 1 to 2.5 wt. % sulfur to the gear oil, wherein the sulfurized olefin comprises a mixture of sulfurized olefins of formula R1-Sx-R2 where R1 and R2 separately are derived from 3 to 5 carbon atom containing olefins and x is an integer of between 3 and 7, with the proviso that the sulfurized olefin will have a sulfur content of from about 40 to about 50 wt %,
• c. 100 to 10,000 ppm of an alkanolamine or diamine containing booster of Formula II
• where:
• X is a hydroxyl or amino group or a primary amine;
• Y is a hydroxyl or amino group or a primary amine;
• W and Z are, individually, an H atom or alkyl group of 1 to 4 carbon atoms with optional substitution of additional hydroxyl or amino groups, and so long as if X and Y are both hydroxyl, then at least one of W and Z cannot be H or —CH3, and
• the sum of (carbons in W)+(carbons in Z)=10 or less, and
• d. at least one of:
• i. 0.1 to 2 wt % of a metal alkylthiophosphate,
• ii. 0.1 to 8 wt % of a thiadiazole-functionalized dispersant,
• iii. mixtures of (i) and (ii)
• wherein the lubricant comprises a total sulfur level of about 1 to about 3 wt %.