An important design task of gearbox development is the optimization of its lubrication across a wide range of operating conditions, lubricant viscosities, oil fill levels, vehicle grades and dynamic maneuvers. Industry-wide, a drive to digitalize testing means that new CFD methods are required to economically reproduce this task in a virtual environment. These requirements have driven the market to consider particle-based CFD simulation methods, which are particularly well suited to handle free surface flows involving complex geometries. PreonLab is one such particle-based CFD code based on implicit incompressible smoothed particle hydrodynamics. PreonLab offers a uniquely efficient simulation tool that enables transient simulation of real-world scenarios such as monitoring lubrication in e-drive gearboxes.