Red Line 50205 Manual Transmission Lubricant (MTL) Gear Oil - 1 Gallon, (Pack of 4)
Red Line's Manual Transmission Lubricant is a 70W80 GL-4 Gear Oil (SAE 5W30/10W30 engine oil viscosity) designed for use in manual transmissions and transaxles. It provides excellent protection of gears and synchronizers and its balanced slipperiness provides a perfect coefficient of friction, allowing easier shifting. This lubricant is popular in many BMW transmissions and in most Honda and Acura transaxle applications.  MTL is the correct product for Big-Twin primary chaincase. Big-Twin transmissions should use Red Line Heavy Shockproof, while Sportster and Buell Tranmission should use Red Line 75W90 GL-5 gear oil.  Red Line Oil's MTL and MT-90 allow proper shifting over the entire temperature range which the transmission will experience due to its wide viscosity. The synthetic base oils used have a very high viscosity index which provides relatively constant viscosity as temperature changes. MTL is a low 70W at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. MT-90 is a thicker 75W90 version of MTL. The shear stability and oxidation stability of these products are excellent, thus the physical characteristics of Red Line MTL and MT-90 will change little with use.