Spin of An Object (UnScrew Application- Animation)

Hi,

I am finishing an animation. I have these four knobs that I want to screw onto another part. When I have all four knobs selected, I can see the animation work perfectly fine, it shows the quick motion of the object turning. However, when I have my ojects unselected, and want to just normally watch my animation (the effect is included on the timeline), the objects do not really replicate the quick spin. It just kindof lobbies on, it does not show that quick turn (unless I have all four objects selected). Any advice what this might be?

Thank you,

Liza