its just the noise the BTR box makes in first..

its one of those things you dont argue or question, it just does.. like franks post whoring...

I think it's the Planetary gears. And apparently new ones can even be louder

With my drive-line vibrations, been told by a specialists that is could be the Torque Converter when it locks up in 4th gear at 75 - 85kmh. Cars too slow when it locks up, acting like a manual box when a too higher gear is selected when the cars is going too slow for it. I get that rumble, vibration.
Don't know what to do to make that better yet, but working on it with your help guys.