The paper presents the results of studies on the behaviour of upgrading admixtures of mul-tiseason gear oils widely used in gear mechanisms of selected types of cars and buses. The influence of the content of zinc dialkyl ditniophosphate on the extent of exploitation wear of gear parts as a function of mileage and exploitation period was investigated.
The contents of such chemical elements as Cu, Zn, Fe, Ca and Sc in the investigated oils change with operational time of the whole gear system. Quantitative description of those changes gives valuable information about lubrication properties of the oil. The determination of the above elements concentrations was carried out by means of instrumental neutron activation analysis (INAA).