Posted in garage too without much success so hopefully posting in a MK2 specific section will be easier for people to find

The car started squealing today, thought alternator belt but it doesn't do it on idle, and I don't have power steering etc or anything much that would strain the alternator enough to make it slip as far as I know!
Because it's only when I move, and the thrust bearing has been grinding for quite some time (just not had the money for a clutch kit with christmas and everything!) I took my step dad out for a run so he could hear it, and he suggested it might be that.
I don't know enough about it to be honest, but would that make sense? The only reason I'm asking is because I'm so worried about it being belt related! It recently had a new belt AND new cylinder head, gaskets etc because the cam belt sheered a load of teeth!! Apparently it was meant to have been changed when some other work was done on the engine but it never was!! Garage didn't wanna know though obviously!!
Anyway, would appreciate any comments or help on this - especially if you think it may well be the thrust bearing. It's been grinding now since about.... September I suppose!!