Installing the shift cam. In this photograph, I have inserted the holding pawl to show how it fits. It can be useful to have the holding pawl installed because it can be used to keep the cam from rotating. The cam return spring has already been installed at the bottom of the cam (note that the spring tab that fits into the pivot is visible through the center hole). Because the cam axle hasn't yet been installed, you have to hold the cam in position with your thumb. The holding pawl can simply be moved out of the way during installation, since it doesn't have a spring yet, or it can be installed after the shift cam has been placed in the shifter.

Installing the shift cam.  In this photograph, I have inserted the
holding pawl to show how it fits.  It can be useful to have the
holding pawl installed because it can be used to keep the cam from
rotating.  The cam return spring has already been installed at the
bottom of the cam (note that the spring tab that fits into the pivot
is visible through the center hole).  Because the cam axle hasn't yet
been installed, you have to hold the cam in position with your thumb.
The holding pawl can simply be moved out of the way during
installation, since it doesn't have a spring yet, or it can be
installed after the shift cam has been placed in the shifter.