Cylindrical gear transmissions are related to mechanical transmissions by engagement. The kinematic feature of these transmissions is the rolling of involute profiles of conjugated gear wheels with sliding, the speed of which changes over time. Uneven sliding of tooth profiles over time causes wear and reduces the wear resistance of the transmission as a whole. To reduce wear of tooth profiles, lubricant is used. Traditionally, gear lubrication of reducers is carried out by the crankcase method, in which the gear wheels are immersed in lubricant poured into the housing. For transmissions operating at peripheral speeds of more than 12.5 m/s and high contact loads (more than 500 MPa), a jet lubrication method is used, using circulation systems. Jet circulation lubrication systems are structurally more complex than crankcase lubrication systems and are a closed system that includes: sprayers, filters, distributors and pipelines, pumping and volume-control equipment. Studies show that the efficiency of such systems largely depends on the flow rate of the supplied lubricant, but there are no recommendations for establishing its boundaries depending on the geometry of the gear engagement. In order to study the effect of lubricant supply volumes during jet lubrication on the wear of gear engagement, gears with a nominal torque of more than 100 kNm, experimental and mathematical modeling of cylindrical gear engagements with large modules was carried out.