I just bought a c-360 canister filter a few days ago and the impeller came apart. The rubber deals on each end came off, the round "spacer" thing came off, and the shaft came out. Is this normal? Can I just put it back together, or is this not good and I need a new one? Also, the shaft seems too long. The impeller slides back and forth on it. Is this supposed to happen? Thanks guys....!