Alternator Pulley sheared off!?!

[kk2002s]

Seems the alternator clutch pulley seized
It looks like you can buy just the alternator clutch pulley for around $40
That does seem odd that much rust is up there. Maybe the water pump is leaking onto the belt?
Don't think you need to immediately jump to replacing all spinning things BUT you should spin and listen to see if any others are coming to their end of life

You may want to replace the belt as well

[Brian in Tucson]

If the alt. clutch had seized, wouldn't the alternator still turn? Does the alternator turn easily and smoothly?

I don't think I'd buy a new alt. clutch before I answered these questions. More likely I'd look for a reman'd alternator. And check out the operation of all the other rotating thingies on the front of the engine.