Issues with Vex clamp on gearbox and 4 inch wheel

[steelerborn]

Due to not having a lot of access to a machine shop we decided to purchase products from VexPro and used their 4" mecanum drive base example as our frame (same dimensions and same parts). After some driving and wearing the wheels down a little bit (not an extreme amount) we noticed that the gears were actually in contact with the floor as well.
We used the same dimensions that VexPro used and the exact same sized gears with the new 4" mecanum wheel.

I have sent an email to vex about the issue but have not heard back.

Are any other teams using the VexPro clamp on gearbox with a 4" mecanum wheel experiencing similar issues?

Here is an image of us trying to slide a piece of paper under the gear.

https://onedrive.live.com/redir?resid=CEBED2B660E90E05!13247&authkey=!AFrATl iSoUxXp0Y&v=3&ithint=photo%2cjpg