Lubricant for manual or automated manual transmissions

Abstract

A method for lubricating a manual transmission or automated manual transmission apparatus having metallic synchronizers which comprises supplying to said transmission a lubricating composition comprising a major amount of an oil of lubricating viscosity containing effective amounts of two ZDDP's, a thiadiazole corrosion inhibitor, a fatty acid primary amide and at least one each of a supplemental anti-wear agent, a dispersant, an antioxidant and a metal detergent.

1 . A method for lubricating a manual transmission or automated manual transmission apparatus having metallic synchronizers which comprises supplying to said transmission a lubricating composition comprising a major amount of an oil of lubricating viscosity containing effective amounts of: 
 (a) a ZDDP (zinc dialkyldithiophosphate) derived from primary alkyl alcohols,    (b) a ZDDP derived from 50 wt. % or more secondary alkyl alcohols,    (c) a thiadiazole corrosion inhibitor being a 2,5-dimercapto-1,3,4-thiadiazole or derivative thereof, and optionally,    (d) a fatty acid primary amide friction modifier active at low temperatures,    (e) at least one supplemental anti-wear agent,    (f) at least one lubricating oil dispersant,    (g) at least one antioxidant, and    (h) at least one metal detergent.    
   
   
       2 . The method of  claim 1  wherein the synchronizers are brass or sintered bronze.  
   
   
       3 . The method of  claim 1  wherein there is present 0.1 to 1.0 wt. % of the (a) component.  
   
   
       4 . The method of  claim 1  where there is present 0.01 to 0.5 wt. % of the (b) component.  
   
   
       5 . The method of  claim 1  wherein the alkyl groups of the (a) and (b) components have 3 to 12 carbon atoms.  
   
   
       6 . The method of  claim 1  wherein there is present 0.01 to 1.0 wt. % of the (c) component.  
   
   
       7 . The method of  claim 6  wherein the (c) component is 2,5-bis-(nonyldithio)-1,3,4-thiadiazole.  
   
   
       8 . The method of  claim 1  wherein there is present 0.01 to 1.0 wt. % of the (d) component.  
   
   
       9 . The method of  claim 8  wherein the (d) component is oleamide.