my spur gears ( both X axis and Y axis) are being chewed up at an alarming rate. That they are being chewed up at all makes me wonder what might be the cause. Any one else have this issue?

my y got chewed up about 4 months after i had my machine ,just last week my machine was stalling at the end of the Y axis,they had to enlarge the hole where the gear went through,something is slightly off there .
Are you pushing it ,what router or spindle do you have--you should not be having that trouble