Detergents are not added to lubricants designed for blower gear cases. This is for two reasons.
First, it would serve little purpose. Detergents are added to motor oils to disperse and suspend contaminants introduced primarily by combustion by-products and fuel contamination, neither which are present in a PD blower gearcase.
Second, the particular means that the blower uses (slinger bar & gear toss-up) to diffuse the oil to all lubricated parts would cause a detergent oil to foam profusely, leading to poor and inconsistent lubricative film strength. The entrapped air within a foam produces voids such that the bearing metal surfaces are not reliably separated by a pure oil film. Moreover, the excessively foamed oil loses a tremendous amount of its ability to transfer the heat from the bearings, as it performs a coolant dispersion function.
