Copying rotation axes from a wheel to steering knuckle is giving crazy results

I’m making a vehicle, and I want the steering knuckle to copy the rotation of the wheel, so in the anim blueprint I used a bone driven controller to copy the wheel Z rotation (yaw) to the steering knuckle so that it turns with the wheel. However, the rotation value of the wheel seems to swap between 180 and 0 (and -180), which is causing my knuckle to flip sides and generally behave badly. Is there a better way I could be doing this?