Shaking up and down

Hello,

I'm trying to find the right behaviour.

I'm shaking an object up and down. It moves only a little as it is the vibration of a motor.

I can't use the earthquake because I have some blur filters and they will mess up the scene.

Would it be oscillate ? Tried this but it is less than perfect.

I can always keyframe the whole thing but if I can avoid that.

Thanks.