someone with 500 posts should know how to set gear mesh???
there should be just a noticeable amount of play between the gear at every corner. the spur gear isn't 100% similar all around. in some spaces you can too much or too little depending on how tight or loose it is. just noticeable play. some people use looseleaf paper between the gears and press together. you should be able to rock the spur gears back and fourth while the pinion is help still.