The Red Line 75W140NS is a GL-5 fully synthetic gear oil that has been designed to provide the highest degree of protection in vintage and historic vehicles, using synchro gearboxes, from the mid 1930's to early 1950's. Also for use in competition cars with plate type limited slip differentials. Provides maximum diff lock up as it contains no friction modifiers. Ideal for clutch type LSD's in competition cars as it provides maximum lockingPopular for use in historic and vintage synchro gearboxesCan be mixed with red Line 75W90NS  or MT-90 to aid viscosity and help quieten noisy gearboxes This oil has a high viscosity index (VI), this is to provide a constant viscosity and film thickness in varying temperatures.Specifications: API GL-5Recommendations: API GL-5 and MT-1, MIL-PRF-2105E, SAE J2360, Rockwell 0-76-C, SAE 140 applications, Historic and vintage synchro transmissions1 Quart (0.94 litre) BottleTechnical Data Sheet