How do I use quaternion rotation for bone transforms in the Anim Graph?

I need to rotate a bone around a local axis but the rotation pops at 180 degrees. Gimbal lock? How can I set it to rotate smoothly in the Anim Graph.

Here’s a link to a video showing my problem.



8 years later and here we are. Did you ever find a solution to this? I’ve been stuck trying to find a way around this for 2 days and getting nowhere!