Rheological Properties of Automatic Transmission Fluid 680437
Automatic transmission fluids are subject to temporary variations in viscosity because of their non-Newtonian characteristics. In addition, permanent viscosity losses are encountered in service due to shearing stresses on the polymer present. The non-Newtonian variations in viscosity over the wide ranges of shear rate and temperature encountered in service have been determined for fluids typical of “new” and “used” conditions. This new information gives better understanding of actual operating conditions, and permits a re-examination of the validity of current specifications.