Power Transmission Fluids

Abstract

A fluid composition for all-wheel drive wet multi-disk brakes and/or differentials having improved characteristics, additive concentrates for all-wheel drive vehicles and methods for improving fluid characteristics for all-wheel drive vehicles. The fluid composition is a base oil having therein an extreme pressure/antiwear additive package and a limited slip/antiwear additive package. The additive composition is substantially devoid of dithiophosphate components and has from about 1000 to about 2000 ppm phosphorous from phosphorous-containing components based on a total weight of the fluid composition.

1 . A fluid composition for all-wheel drive wet multi-disk brakes and/or differentials, comprising a base oil, an extreme pressure/antiwear additive package, and a limited slip/antiwear additive package, wherein the composition is substantially devoid of zinc containing additives and is substantially devoid of dithiophosphate components and comprises from about 1000 to about 2000 ppm phosphorous from phosphorous-containing components based on a total weight of the fluid composition. 
   
   
       2 . The fluid composition of  claim 1 , wherein the base oil comprises one or more of a natural oil, a mixture of natural oils, a synthetic oil, a mixture of synthetic oils, and a mixture of natural and synthetic oils. 
   
   
       3 . The fluid composition of  claim 2 , wherein the natural oil comprises one or more of a mineral oil, a vegetable oil, and a mixture of mineral oil and vegetable oil. 
   
   
       4 . The fluid composition of  claim 2 , wherein the synthetic oil comprises one or more of an oligomer of an alphaolefin, an ester, an oil derived from a Fischer-Tropsch process, a gas-to-liquid stock, and a mixture thereof. 
   
   
       5 . The fluid composition of  claim 1 , wherein the extreme pressure/antiwear additive package and the limited slip antiwear additive package comprises an amine antiwear agent comprising a mixture of C 12 -C 14  tertiary alkyl primary amines. 
   
   
       6 . The fluid composition of  claim 1 , wherein the composition comprises from about 0.5 to about 5 wt. % of the dialkyl hydrogen phosphite based on a total weight of the fluid composition. 
   
   
       7 . The fluid composition of  claim 1 , wherein the extreme pressure/antiwear additive package comprises from about 70 to about 90 weight percent of a sulfur-containing extreme pressure agent based on a total weight of the additive package. 
   
   
       8 . The fluid composition of  claim 1 , wherein the composition comprises from about 0.5 to about 5.0 weight percent sulfur based on a total weight of the fluid composition. 
   
   
       9 . The fluid composition of  claim 1 , wherein the composition comprises a phosphate other than a dithiophosphate. 
   
   
       10 . The fluid composition of  claim 1 , wherein the fluid composition comprises from about 0.5:1 to about 1:1 extreme pressure/antiwear additive package to limited slip/antiwear additive package in the fluid composition. 
   
   
       11 . An all-wheel drive differential comprising the fluid composition of  claim 1 . 
   
   
       12 . A multi-disk brake for an all-wheel drive vehicle comprising the fluid composition of  claim 1 . 
   
   
       13 . A vehicle comprising the multi-disk brake of  claim 12 . 
   
   
       14 . An additive concentrate for an all-wheel drive vehicle fluid comprising:
 an extreme pressure/antiwear additive package; and   a limited slip/antiwear additive package,   
     wherein the fluid containing the additive concentrate is substantially devoid of zinc containing components and is substantially devoid of dithiophosphate containing components. 
   
   
       15 . The additive concentrate of  claim 14 , wherein the extreme pressure/antiwear additive package and the limited slip/antiwear additive package comprises an amine antiwear agent comprising a mixture of C 12 -C 14  tertiary alkyl primary amines. 
   
   
       16 . The additive concentrate of  claim 14 , wherein the concentrate comprises from about 0.5 to about 5.0 wt. % of the dialkyl hydrogen phosphite based on a total weight of the concentrate. 
   
   
       17 . The additive concentrate of  claim 14 , wherein the extreme pressure/antiwear additive package comprises from about 70 to about 90 weight percent of a sulfur-containing extreme pressure agent based on a total weight of the extreme pressure/antiwear additive package. 
   
   
       18 . The additive concentrate of  claim 14 , wherein the extreme pressure/antiwear additive package comprises a fatty acid phosphate. 
   
   
       19 . The additive concentrate of  claim 14 , wherein the concentrate comprises from about 0.5:1 to about 1:1 extreme pressure/antiwear additive package to limited slip/antiwear additive package. 
   
   
       20 . A fluid composition for comprising from about 0.5 to about 15 wt. % of the additive concentrate of  claim 14 . 
   
   
       21 . A method for lubricating wet multi-disk brakes and/or differentials comprising providing a lubricant composition comprising an extreme pressure/antiwear package and a limited slip/antiwear additive package, wherein the limited slip/antiwear additive package comprises a dialkyl hydrogen phosphite, and wherein the limited slip/antiwear additive package provides improved high temperature performance for the lubricant composition. 
   
   
       22 . The method of  claim 21  wherein the lubricant composition containing the limited slip/antiwear additive package maintains API GL-5 performance characteristics. 
   
   
       23 . The method of  claim 21 , wherein the lubricant composition is substantially devoid of zinc and dithiophosphate components. 
   
   
       24 . The method of  claim 21 , wherein the lubricant composition comprises from about 0.5 to about 5.0 weight percent sulfur from sulfur components based on a total weight of the lubricant composition. 
   
   
       25 . The method of  claim 21 , wherein the lubricant composition comprises from about 1000 to about 2000 ppm total phosphorous from phosphorous-containing components.