Custom Gearbox Problems

[baronep]

For this season we had some custom gearboxes manufactured using the Andy Mark toughbox parts, making the design integral to the frame for weight saving reasons. However, after putting them together we noticed that they are very, very noisy. I have heard that this is pretty common with new toughboxes, but it still seems outrageously loud. I will be running them on the bench to wear them in tomorrow, but does anyone have any ideas why they would be running so loud. (And yes we did use grease, white lithium grease specifically and a lot of it)