Composition and method for lubricating automotive gears, axles and bearings
The disclosed technology relates to a lubricant composition for automotive gears, axles and bearings, the lubricant composition containing an oil of lubricating viscosity and a metal thiophosphate compound, such as zinc dialkyldithiophosphate, as well as a method of obtaining extreme pressure performance in automotive gears, axles and bearings at lower sulfur content than is typical, by lubricating such automotive gears, axles and bearings with a lubricant composition containing a metal thiophosphate compound, such as zinc dialkyldithiophosphate.
1. A lubricant composition for an automotive gear comprising
a. an oil of lubricating viscosity;
b. a zinc thiophosphate to provide from 150 ppm to 3000 ppm zinc, and
c. a non-metal phosphorus containing compound, wherein the non-metal phosphorus containing compound comprises at least one of a phosphorus amine salt, a sulfur containing phosphorus amine salt, a phosphite, a phosphonate, a sulfur containing phosphite, a sulfur containing phosphonate, non-metal dithiophosphates, or mixtures thereof,
d. between 0.07 and 0.5 wt. % of a thiadiazole or derivative thereof, and
e. a sulfurized olefin between 2 and 3 wt. %,
wherein the lubricant comprises a total sulfur level from all additives (i.e., not including base oil) of about 0.5 to about 2 wt % and a total phosphorus level of about 500 ppm to about 1500 ppm.
2. The lubricant composition of claim 1 , wherein the zinc thiophosphate comprises zinc dialkyldithiophosphate.
3. The lubricant composition of claim 1 , wherein the zinc dialkyldithiophosphate comprises, consists essentially of, or consists of a secondary zinc dialkyldithiophosphate.
4. The lubricant composition of claim 1 , wherein the lubricant comprises a total phosphorus level of greater than 1000 ppm.
5. The lubricant composition of claim 1 , wherein the lubricant is substantially detergent free.
6. The lubricant composition of claim 1 , wherein the metal thiophosphate provides from about 15 to about 80% of the total phosphorus in the composition.
7. The lubricant composition of claim 1 , further comprising a detergent.
8. The lubricant composition of claim 1 , further comprising a borated dispersant.
9. A method of lubricating an automotive gear, axle and/or bearing, comprising supplying to the automotive gear, axle and/or bearing the lubricant composition of claim 1 , and operating the automotive gear, axle, and/or bearing.
10. The method of claim 9 wherein the driveline device comprises an axle.
11. The method of claim 9 , wherein the driveline device comprises a bearing.
12. The method of claim 9 , wherein the driveline device comprises a gear.
13. The method of claim 9 , wherein the driveline device comprises a manual transmission.
14. The lubricant composition of claim 1 , wherein the lubricant comprises a total sulfur level from all additives of about 0.5 to about 0.75 wt. %.