I just have a quick and simple question. My shift star shaft has a small chunk taken out if it where the woodruff key sits. Is this why they started to weld them on?
My first guess would be cheaper production, no hole, threads, screw. never looked at a welded one to see how they index it for welding.
Haven't seen anything about the key, but some have had the screw come loose
They started to weld the shift stars on in 2003-2006. From 1988-2002 all of them had the screw style. Nothing wrong with welding them on if that one has play. If it doesn't have any play then I would leave it alone. If you take it apart and do use the screw again be sure to use some loctite.
If you weld it and you have access to a TIG welder, that's your best route. Due to the small amount of weld, MIG or flux core will not get hot enough in the short amount of time to penetrate well. This will be a reoccurrence when the tack breaks free from lack of penetration.