A UTTO transmission oil ensuring lubrication of both transmissions and hydraulic circuits in construction machinery. It contains extreme pressure additives which retain the protective film and reduce shearing effects on the gears, even under load. Its anti-wear and anti-corrosion properties ensure the gear protection. Its anti-foaming properties help prevent oil overflow and losses, which would be detrimental to the resistance of the gears. It possesses a friction modifier ensuring that immersed brakes work without chattering or squeaking.