gearbox
Be very carefull, I think Bell do not allow road transport of certain models, the 206 I think is one,because the planet wheels and bearings are not designed to take the shock loads that can be experienced on the road.
This was brought up years ago, on discussions about keeping down position costs on some jobs, but was a no goer as the gearbox would have to be removed.
It is apparently burried in the maintenance manuels somewhere, I am no expert on spanner matters but it would be worth asking someone who is.