ABSTRACT
This chapter aims to provide a general overview of modern transmission lubricants; how they are specifically tailored to the variety of transmissions in the marketplace, and how they are expected to evolve to meet future transmission requirements. It provides a basic description of the different chemical constituents used to create a lubricant. The chapter discusses a basic overview of transmission hardware. Transmission lubricants, which enable the transfer of power from the engine to the vehicle’s wheels via a combination of gears, hydraulics, and clutch friction typically have a performance additive treat rate of 5 to 15% and 2 to 20% viscosity modifiers. Basestocks used to formulate transmission fluids are normally mineral and/or synthetic oils. The low-temperature viscometric requirements for the transmission will influence the type of basestock used. Various elastomeric materials such as nitrile, silicone, polyacrylate rubbers, and fluoroelastomers are used in transmission seals that prevent both internal and external leakage of fluid.
