High-tech synthetic-based lubricant for gearboxes and axles. Formulated based on a TDL (Total Drive Line) concept, which allows the same product to be used in gearboxes and axles: (GL-4 and GL-5 compliant product) without any risk of corrosion, in particular of synchromeshes. The synthetic nature of the base gives the product a greater resistance to high temperatures without risk of oxidation or of deposit formation (leaving the gears very clean) and also provides an excellent shear resistance of the oil film. SYNTHEGEAR meets the specifications of the main gearbox and axle manufacturers, and thus enables the most stringent oil change intervals they recommend.