I want to change the orientation of my object to a specified direction.

Say I have an axle of a train whose *normal* orientation is set off by 90° from the *global* orientation:

![enter image description here][1]

The green arrow (Y-axis) points to the back of the train (along the global X-axis). But I want it to point to the sides of the train, so all I want is to rotate the orientation by 90° *without* rotating the object itself.

In other words, I want the normal and global orientation of the axle to be the identical:

![enter image description here][2]

Is this possible and if so, how?

Background:
The game engine to use this model will move the bogies and the axles according to their orientations. After importing this train into the game the axles rotated 90° off.

  [1]: https://i.sstatic.net/cXMSX.png
  [2]: https://i.sstatic.net/LMYlA.png