+1 for grub screw. My drilling abilities need work, but I put 2 in each hub. About 60% of the slop went away. I suggest a fine tipped punch to indent for drilling or it wonders. You might have to drill a little into the far side of the pin hole for the tap to be able to go far enough in to thread all the way. A dab of blue locktite on the set screws and dont. I did go buy a drill press vice for $16 do hold the hubs still though. Al said about $30 in parts to fix my $30 hubs, lol