I tried the bang the crap out of it approach as well. Now I just ordered a new spray arm a carb parts kit. This brass bushing is too soft to force into the housing. Next time, I will try to stick brass bushing it in the freezer first, then heat up the spray arm. The housing will expand wider from the heat, and the brass bushing will compress with the cold - maybe enough to fit! That might be the only useful thing I learned from 4th grade science. I will call Horizon Hobby if this does not work, and let you know.