i got my mavic today.
When i tun on my mavic the gimbal scratches the case for 1-2 seconds.
The handy shows the warning "Gimbal motor overload" for 1-2 seconds.
After that, the gimbal centers and everything is ok.
If you are getting a warning and the gimbal is scratching the cover - this is not normal and will most likely need to be returned for service or replacement.