Lubricating Composition Containing an Ester

Abstract

The invention relates to a method of lubricating a limited slip differential comprising supplying to the limited slip differential a lubricating composition containing (a) an oil of lubricating viscosity, and (b) a C4-30-diester of a dicarboxylic acid. The invention further provides for the use of the C4-30-diester of a dicarboxylic acid as a friction modifier, typically in a limited slip differential.

Description

FIELD OF INVENTION[0001]The invention relates to a method of lubricating a limited slip differential comprising supplying to the limited slip differential a lubricating composition containing (a) an oil of lubricating viscosity, and (b) a C4-30-diester of a dicarboxylic acid. The invention further provides for the use of the C4-30-diester of a dicarboxylic acid as a friction modifier, typically in a limited slip differential.BACKGROUND OF THE INVENTION[0002]A limited slip differential in a vehicle typically employs a wet multi-plate clutch, i.e., clutch plates are immersed in a lubricant. The limited slip differential typically has bevel gear or spur gear planetary systems which distribute the drive torque evenly to the two driving wheels irrespective of their rotational speed. This makes it possible for the driven wheels to roll during cornering without slip between the wheel and road surface in spite of their different rotational speed. In order for the slip to be controlled lubri...

AI Technical Summary

Benefits of technology

[0007]The inventors of this invention have discovered that a lubricating composition and method as disclosed herein is capable of providing an acceptable level of at least one of (i) lubricant thermal stability, (ii) lubricant oxidative stability, (iii) high static coefficient of friction, (iv) fuel economy, (v) deposit control, (vi) seal compatibility, (vii) cleanliness and (viii) low tendency towards noise, vibration and harshness (NVH) often manifested as chatter (i.e. an abnormal noise typically referred to as a low-frequency “growl” and “groan”, particularly during higher-speed cornering manoeuvres). The inventors have also discovered that unexpectedly the lubricant composition and method disclosed herein may also be suitable for limited slip systems having one or more distinct plate materials. For example the plate materials may be steel, paper, ceramic, carbon fibers and systems employing a mixture of plate types such as steel on ceramic, carbon fibers in paper, or steel on paper. In one embodiment the plate material may be paper.

Problems solved by technology

The whole lubricant disclosed therein is reported to decrease power loss due to friction, therefore conserving fuel consumption.

Images