Oda112

That bolt is reverse thread, on the M273 it's a 25 or 27 torx if I remember correctly. You are correct in assuming that you don't need to replace the centrifuge (unless it's clogged) but the breather cover needs replacing as the diaphragm gets brittle and shrinks letting oil pass it. I replaced the whole system+hoses on mine just for peace of mind. ECS tuning was selling the complete kit at the time.

atraudes

Oh dang, it being reversed threaded totally explains it! My instinct to not force it was a good one then

Oda112

Good instinct! They did it that way because the centrifuge (oil separator) lives at the end of the exhaust camshaft.