I took my assembly to a machine shop. The machinist showed me that the original bushing was steel with a brass insert. The new bushings are just brass and they replace only the brass, which is very thin. In addition, they are the type made out of pressed powder, I think that they are called sintered. He also explained to me that they do not have a lot of strength when made out of that material. He may remove the shaft and turn it down as a solution.
