Boron containing automotive gear oil

Abstract

The disclosed technology relates to an automotive gear oil, which may be used, for example, in heavy duty manual transmissions and axles, and includes an oil of lubricating viscosity, 1 wt % or less of a dispersant, and at least one boron containing compound.

What is claimed is: 
     
         1 . An automotive gear oil for lubricating an automotive gear comprising
 a. an oil of lubricating viscosity   b. 0.025 to 0.9 wt. % of a succinimide dispersant, and   c. about 0.2 to 2.0 wt. % of at least one boron-containing compound in an amount sufficient to provide from about 75 ppm to about 500 ppm of boron to the automotive gear oil, wherein that at least one boron-containing compound is a borate ester of formula I,   
       
         
           
           
               
               
           
         
          wherein each R, independently, is a C 3  to C 12  alkyl, and 
         d. 0.01 wt % to 0.5 wt % of a dimercaptothiadiazole or derivative thereof. 
       
     
     
         2 . The automotive gear oil of  claim 1  wherein the automotive gear oil has a kinematic viscosity at 100° C. of from 8 cSt to 24 cSt. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . The automotive gear oil of  claim 1  further comprising at least one phosphorous containing compound present in an amount to deliver 100 to 1500 ppm of phosphorus to the automotive gear oil. 
     
     
         7 . The automotive gear oil of  claim 6 , where the phosphorous containing compound comprises at least one of: (1) a C 3-8  hydrocarbyl phosphite, (2) a phosphite ester composition that comprises the reaction product of a monomeric phosphorous acid or an ester thereof with at least two alkylene diols, (3) a phosphate ester amine salt, (4) a pyrophosphate amine salt, or (5) mixtures of any of (1) to (4). 
     
     
         8 . (canceled) 
     
     
         9 . The automotive gear oil of  claim 1  further comprising a viscosity modifier. 
     
     
         10 . The automotive gear oil of  claim 1  further comprising a friction modifier. 
     
     
         11 . The automotive gear oil of  claim 1  further comprising a detergent. 
     
     
         12 . A method of lubricating an automotive gear comprising supplying to the automotive gear a composition of  claim 1 , and operating the automotive gear. 
     
     
         13 . The method of  claim 12 , wherein the automotive gear is in a manual transmission. 
     
     
         14 . The method of  claim 12 , wherein the automotive gear is on an axle. 
     
     
         15 . The method of  claim 12 , wherein the automotive gear is on a differential.