Lower guide for planetary gear shaft has come lose

I'm not sure if I am correctly referring to part in question, but this piece (see pictures) appears to have been originally press fit in (or maybe welded/attached?) but it has come lose and now I can't get it to stay in place. As a result, there is a lot of play in the shaft... It would help if I knew how it was originally attached. Most exploded views seem to indicate that this is not a part meant to be replaced...

Any suggestions?