Do Harleys Leak Oil?
Harleys do not leak engine oil. Early Harleys used an automatic lubrication system that drew oil from the oil pump to lubricate the primary chain. What seems like oil leaking from the motorcycle is actually excess oil dripping off from the primary chaincase.The oil would drop off from the primary chain into the primary chaincase, which had a drain hole that allowed oil to drop to the floor.
The resulting puddles on the floor lead people to believe that Harleys leak oil.
Do Harley-Davidson Motorcycles Typically Leak Oil?
As we said earlier, Harley critics describe that oil leaks are not oil leaks in the truest sense.Do Harleys leave oil puddles on the floor when parked? Yes.
However, these oil puddles are not the result of a systemic defect in the motorcycle design. Rather, they are a by-product of Harley’s automatic lubrication system.
Let’s explain.
Oil & Lubrication Distinction
Early Harley Big-Twin engines had a separate engine and transmission connected via a primary drive chain.This chain transferred power from the engine to the transmission. As this chain was prone to overheating, Harley engineers had to devise a way to keep the chain constantly lubricated.
The engineers ran a tube from the oil pump into the back half of the chain cover. This way, oil from the oil pump would drip over the primary drive chain to lubricate it.
The oil that dripped off the chain would collect in the primary chaincase and finally onto the ground; the chaincase had a drain hole. Therefore, the oil puddles are merely the result of Harley’s automatic chain oiling system.
Many Harley critics do not know of the automatic lubrication system. Hence, you’ll hear a lot of jokes about “those big, old, leaky Harleys.” Don’t be surprised. The idea that Harleys are big, noisy, oil-leaking bikes is old, and many now take it as the gospel truth.
Harley-Davidson stopped using automatic chain oilers in 1964, and all lubrication had to be done by hand.
