A through hub fill hole and air vent having an enlarged fluid diffusion path is provided for spindle motors. Oil leakage and evaporation from a motor is reduced. In an aspect, oil is retained under conditions of at least a 1000 G shock event. In an aspect, the hub fill hole has a varying diameter and geometry, and is angled, further reducing oil leakage. In an aspect, an additional cavity is employed within the hub, for maintaining rotor rotational balance. The process of filling oil into a spindle motor is made easier from a motor set up and tooling perspective. Removal of the hub and other motor components is not necessary for filling a motor. Large diameter oil fill dispenser heads, subambient and ambient fill processes, and micro dispenser fill processes may be utilized. A measured and controlled amount of oil can be dispensed, reducing variability in the motor filling process.