It's been awhile since I took a Mag pump apart, but I don't think there is too much damage it can do as everything else is sealed. Only thing that may happen is the other blades break off while it is so wobbly. I have an Iwaki pump where one of the fins broke off of the impeller. Overtime, the being off balance caused the others to break off as well. I think my pump sucked in a hermit crab that I had thrown in the fuge. Always good to take pumps apart and clean them every so often. Gives you a chance to inspect them for any damage as well.