A vehicle system comprising: a fluid sensor mountable to the vehicle system such that the mounted fluid sensor at least partially extends into a gearbox of a traction motor of the vehicle system, the fluid sensor configured to output data representative of an amount of a lubricating fluid in the gearbox; a positioning system mountable to the vehicle system and configured to output data representative of movement or an absence of movement of the vehicle system; one or more processors configured to determine the amount of lubricating fluid in the gearbox based on the data that is output by the fluid sensor responsive to the data output by the positioning system indicating that the vehicle system has not moved or has moved by less than a designatable distance for at least a designatable, non-instantaneous period of time; and a plurality of axles of the vehicle system; characterized in that the fluid sensors include temperature sensors configured to output data representative of temperatures of the plurality of axles, wherein the one or more processors are configured to compare the temperatures of the axles with each other and identify at least one of the axles as damaged based on comparing the temperatures of the axles with each other, wherein the temperature sensors are configured to measure the temperatures of the axles at different moving speeds of the vehicle system and to output the data representative of the temperatures of the axles at the different moving speeds of the vehicle system to the one or more processors, and wherein the one or more processors are configured to examine the temperatures to identify the at least one of the axles as damaged responsive to the temperatures of the at least one of the axles increasing between at least two of the different moving speeds of the vehicle system while other axles of the axles do not increase between the at least two of the different moving speeds relative to the at least one of the axles. a fluid sensor mountable to the vehicle system such that the mounted fluid sensor at least partially extends into a gearbox of a traction motor of the vehicle system, the fluid sensor configured to output data representative of an amount of a lubricating fluid in the gearbox; a positioning system mountable to the vehicle system and configured to output data representative of movement or an absence of movement of the vehicle system; one or more processors configured to determine the amount of lubricating fluid in the gearbox based on the data that is output by the fluid sensor responsive to the data output by the positioning system indicating that the vehicle system has not moved or has moved by less than a designatable distance for at least a designatable, non-instantaneous period of time; and a plurality of axles of the vehicle system; characterized in that the fluid sensors include temperature sensors configured to output data representative of temperatures of the plurality of axles, wherein the one or more processors are configured to compare the temperatures of the axles with each other and identify at least one of the axles as damaged based on comparing the temperatures of the axles with each other, wherein the temperature sensors are configured to measure the temperatures of the axles at different moving speeds of the vehicle system and to output the data representative of the temperatures of the axles at the different moving speeds of the vehicle system to the one or more processors, and wherein the one or more processors are configured to examine the temperatures to identify the at least one of the axles as damaged responsive to the temperatures of the at least one of the axles increasing between at least two of the different moving speeds of the vehicle system while other axles of the axles do not increase between the at least two of the different moving speeds relative to the at least one of the axles.