Harley Davidson motorcycles 1940 to 1947 inclusive O.H.V. engine / side valve engine. Service Manual - page 2
CAUTION: Shifter control must be kept in correct adjustment; otherwise
driving dogs on shifter clutches will not fully engage in the different
positions and are likely to become damaged from jumping out of
engagement under driving load.
When shifter clutches become worn or damaged to the extent of jumping
out of engagement under driving load, even though shifter control is
correctly adjusted, transmission must be serviced as explained under
"Overhauling Transmission and Clutch," Page 126.
Checking and Adjusting Clutch Control
