The present invention relates to the use of a high level of a silicon-containing antifoam agent in automatic transmission fluid ("ATF") applications. More specifically, the invention relates to a formulation and method for the reduction or elimination of pump whine that occurs in high-pressure pumps used to circulate transmissions fluids in vehicles. The invention also relates to fully formulated ATFs, to transmissions lubricated with such ATFs, and to vehicles containing transmissions lubricated with such ATFs.