gear oil composition, and method for improving oxidative stability properties and sealing compatibility of a gear oil composition

摘要

A gear oil composition is provided. The composition comprises a sufficient amount of an isomerized base oil in a base oil matrix comprising at least at least a polyalphaolefin for the gear oil composition to have for the gear oil composition to have an average volume change in a rubber seal between -10 and +10, a change in shore A hardness between -7 and +10 when tested with SRE NBR28 at 100° C., 168 hours per DIN53521 and DIN53505, a viscosity increase of less than 3% per US Steel S-200 oxidation stability test, a precipitation of less than 1% per US Steel S-200 oxidation stability test, and a Timken OK Load of greater than 60 lb. The isomerized base oil has consecutive numbers of carbon atoms and less than 10 wt % naphthenic carbon by n-d-M. In one embodiment, the sufficient amount of isomerized base oil ranges from 20 to 75 wt. % based on the total weight of the gear oil composition.