I am trying to make a few simple spur gears. When I create the part, and change the pitch diameter, teeth, and so on it will not change. The gear is the same as it first rendered. The only change that is made are the hubs, besides that nothing else will.
FIRST make sure your toolbox gear's tooth geometry doesn't suck. Almost every download or Toolbox-derived gear I've seen has bad teeth that would make a Brit blush.
Attached: gear with actual involute geometry