Shovelhead Oil and Primary Chain

Mike Roen has his 1977 Harley Davidson Shovelhead on the lift for an oil change and for a primary drive inspection and oil change.

Shovelhead models run from 1966 through 1984, with the 1966 to 1969 Shovels having a Panhead bottom end with a Shovel top.

Prior to draining oils, it is important to bring the motorcycle up to temperature. This is important for two reasons. Firstly, if motor oil has sumped into the crankcase, running the bike will return oil to the tank. The second reason is more obvious: Warm, or slightly hot oil will drain more thoroughly than if the oil is cold.

Through the years, there have been a number of different primary drive configurations for the Shovelhead. For some model years, the primary drive is actually belt driven with a dry clutch. Many models, like Mike’s 1977, are set up with a primary chain oiler. This is also considered a dry clutch. The oil that is delivered into the primary drive is only used to lubricate the primary chain. The chain is lubricated with 50 wt motor oil which is delivered from the engine’s oil pump via an oil hose.

Only a small amount of oil stays in the primary compartment at all times. When the oil level in the primary case reaches the level of a lower return/output fitting, the oil is returned to the engine’s oil system.

There is another oil hose at the back side of the inner primary that is for venting. In order to remove the outer primary cover, Mike must first remove the rear exhaust pipe and the left side footrest.

Mike removes the outer primary cover in order to inspect his primary drive, clutch, starter shaft, and starter solenoid. With the cover removed, he can inspect primary chain tracking and more accurately set the primary chain adjustment.