Gearbox joints violently explode when turned more then +-90 degrees about an axis other than the rotation axis

**Original report ([archived issue](https://osrf-migration.github.io/sdformat-gh-pages/#!/osrf/sdformat/issues/100)) by Logan Tutt (Bitbucket: [ltutt](https://bitbucket.org/%7B8fc593ad-742f-4072-8f94-d74bc2b0ef33%7D/)).**

The original report had attachments: [gearbox.world](https://osrf-migration.github.io/sdformat-gh-pages/data/repositories/osrf/sdformat/issues/100/attachments/gearbox.world)

----------------------------------------
If a gearbox joint turns more than 90 degrees about an axis that it is not rotating on, ie the gearbox joint is on the x-axis and the robot turns about the z-axis, the robot starts violently jumping around.

This happens if:

* the model is physically rotated in the world
* it is started rotated in the .world file
* if the links that have the gearbox joints on them are rotated even if the model is not.

This can be seen in the attached file by rotating `joint_02` past the 90 degree mark. Before that point the other joints work fine but once it reaches there the links start flailing wildly