Wow as you say, no wonder it's making noise.
Your pulley has broken. The bit you removed should be unthreaded. And be removed as one piece. If it has (hard to see from pic) then your pulley will just fall off when you take the belt off.
the bearing has collapsed, lots of the balls have fallen out. That's what normally happens. Its an other engineered to fail part Merc can swap quick but hope to charge you 500 quid for.
We will see this come up a lot now they have clocked over 8 years
The pulley is fine the hub got taken out. All bits available separately Not sure if its damaged anything else, would be a shame as nice to keep a decent metal pulley. I have only seen plastic ones.
you could press out the bearing and get a proper quality one from a bearing factor. They might come in well under a tenner
http://euro-klima.pl/en/compressors-spare-parts/bearings/
the hubs are here
http://euro-klima.pl/en/compressors-spare-parts/clutch-hubs-dampers/
Have you removed the belt?
Ah ok, the center threaded portion remains attacked to the compressor. IF you get mole grips on the outer bit (which appears to have broken free from its mate), hold the center piece still and rotate the broken outer piece (or vice versa)
Ah ok, the center threaded portion remains attacked to the compressor. IF you get mole grips on the outer bit (which appears to have broken free from its mate), hold the center piece still and rotate the broken outer piece (or vice versa)
When I turn the center part (indicated by red arrow) by hand nothing else turns so not sure what part you are talking abut holding with the mole grips?
I have removed the snap ring which I though would be holding in the bearing, the bearing slides back and forward a little but doesn't go over the lip!, or should it if forced??
Good news! Give it a pull with a puller and it will come off, its likely fused to the shaft somewhat.
UPDATE:
I managed too renew the A/C Pulley very easily once I figured out how it came off, was a pretty easy fix really. I bought new clutch assembly off of eBay for only £45 so pretty chuffed