Can SYN3 be used in ShovelheadTM engines, 4-speed Big Twin transmissions, and early Shovelhead 5-speed transmissions?
Harley-Davidson did not test SYN3 in these engine configurations. There are a multitude of tests that must be completed before a lubricant can be certified for use in Harley-Davidson engines, primary chaincases and transmissions. Many of these tests require that the components be brand new, and the required quantity of new powertrains for testing and validation could not be procured.
