If you use Lucas HD primary chaincase oil, you can expect smooth clutch action, less slippage, longer chain and sprocket life, plus a much longer oil life. Lucas HD primary chaincase oil is a coolant for the clutch, not a lubricant! It combines a blend of easy-flowing base oils and a Lucas additive that's designed to carry away more heat from the clutch plates and friction plates, offering a more trouble-free clutch life. Protect your investment with HD primary chaincase oil from Lucas Oil--it works!