When installing an S&S gear drive assembly, it is important to measure cam gear lash. First, measure gear lash with only the cam gear installed. Then, measure lash with the cam and pinion gears installed.
Make marks on the cam gear in four locations; 12, 6, 3, & 9 o’clock. Measurements should be made with a dial indicator in those four locations in order to have comparisons. Ideally, a small amount of lash is desirable. Zero lash will result in a more noisy, whining, cam compartment due to binding. Oversized and undersized pinion gears are available from S&S to obtain the desired lash measurement.
Clean and prep the cam and pinion gear retaining hardware with red Loctite and torque to spec. After the cam cover is installed, the S&S gear drive and cam compartment will be complete.
Midway through this video, Mike touches on a topic that his fellow mechanics in the industry will appreciate.
What NOT to Listen For
There are a lot of Harley Davidson owners who ride around looking, smelling, and listening for an issue. It is common for a customer to approach a mechanic, concerned about a motor, transmission, or primary drive sound that is completely normal.
These are air cooled machines. Motors have grown considerably. Cases are thinner than ever to cut weight and the cost of manufacturing. When more aggressive cams are installed in a bike, the motor will be louder. When the cam and pinion gears are constantly meshed together, as opposed to being driven by a chain, the cam compartment will be louder.