any mechanics out there

any help appreciated and appologies as its not clio related.

The starter motor on dads car Pug 1007 (yes i know) has gone. When we turn the engine over it just makes a clunk noise and then nothing happens.

We have fitted a new starter motor today and when we turn over we get a quite loud noise when its turning. Sounds like metal grinding.

As far as we can see its fitted correctly , it can only go in one way,.

Going to strip it off and check on sunday but any idea what prob could be.
 
make sure the starter has the same amount of teeth as the old one...also check the flywheel ring gear teeth are not damaged - not the easiest of jobs - ona 4 cylinder engine theres usually 2 areas where the pinion throws in and the teeth take the brunt of the wear...