motor assembly
 

i have a motor the gear that goes on it and the screw that holds the gear. ive got it so that the gear turns the shaft but how do i keep the gear from sliding off the end of the shaft.
if u could post a video of a motor being assembled that would be great if not oh well.
\btw its going on an xxx-s

The set screw that holds the pinion in place should grip well enough to stop the gear sliding off.

If it doesn't then there must be a problem with the parts being worn or damaged somehow.

i figured it out i didn't use an alen wrench to tighten it (i didn't know was sposed to) but i tightened it and it aint going anywhere now.
thanks anyways