I have an old Craftsman 42-inch deck on a riding lawnmower.
When replacing a spindle, I needed to tighten the spindle nut pretty tight so that it held the belt pulley without any wobble, but noticed that the blade doesn't spin as freely. Perhaps the bearing is also being tightened.
I greased the spacer washer below the pulley which sits on top of the spindle.
Should there be another washer in there between the pulley and the spindle body and spacer washer?
On most there is a 1/8" spacer under the under the pulley to give some space between the pulley and the spindle housing.
However there are at lest a 1/2 dozen 42" decks so starting with a model number would be good.
Craftsman is a brand name, not a model name and it could have been built by Murray, Ayp, Norma, MTD ,etc, etc, etc.
Each one of these companies has a different spindle system and then within a single manufacturer there are variations.