I recently swaped the Bosch alternator on my porsche and had to reuse the old pulley, and it was a beeotch to remove, I finally got it off with some PB blaster, let it soak for 15 minutes, and a small pry bar. I had to use mallet to flatten out those cooling vanes that spin around because the removal bent them a little, but it was pretty easy. someone told me to use 2 or 3 jaw puller, but the one i had was too big to use to remove pulley.

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2005 Mercedes C230k sport sedan, 6 speed
1987 Porsche 924S - 968-engined track car