For dip lubrication system, simple act of reducing the amount of lubricant inside the gearbox can reduce the load-independent losses but at the same time reduce the lifetime of the gear itself due to increasing bulk temperature [1]. Finding a proper lubricant level require understanding of the lubricant flow inside a gearbox. Therefore, 2D-2C PIV of a gearbox model has been done to study more detail the flow. The measurements were taken at three different lubricant levels (centreline, two module of gear, two module of pinion) and three different pitch line velocities (0.6, 1.1, and 1.62 m/s). Viscosity of the test oil (Nytex 810) is maintained at approximately 64 cSt by maintaining temperature at 20°C. The results suggest that flow inside a gearbox is complex, three dimensional and involves effects of rotation, inertia, free-surface dynamics, formation of bubbles and droplets, and also phenomenon of laminar-turbulent transition.