Power Slug Maintenance - Crank Pulley

Apparently the 4D56t diesel engine from Mitsubishi has a known problem with the crank pulley keyway reaming out and the bolt coming lose over time. Doesn’t look like it’s ever been addressed on mine, and now I can hear the crank pulley clattering about on the shaft :-/ Time to pull it off and take a look. Since I’ve got to remove all the belts to do this, I might as well put new one on while I’m in there.
As you can see, the keyway on the old pulley has reamed out creating play in the fitment to the crank shaft. This thing now slides back and forth enough to clatter… along with the loose bolt, this could have been disaster for my engine :-/