Wrong Alternator - Which is best for 1.6td jk

[GTIAlex]

After much head scratching and faffing we have come to the conclusion that someone has previously fitted the wrong alternator to Django. Here he is.



We can't get a belt to fit and the 600mm is too big and keeps slipping/coming off.
When removing the alternator there is what looks like scrapyard paint markings on it, so its obviously come off a shelf at some point which leads us to believe its the wrong one or the wrong pully is fitting.
There are no markings on the alternator other than saying Bosch on it.

SO my question is, which alternator is meant to be fitted and which amp alternator am I best getting.

[Oldiebut goodie]

Buy the belt according to what you need - you obviously need one shorter than 600 mm. Are you getting the correct width also? You may need a 10 mm wide one and you are buying a 9.5 mm wide one.Don't just guess at the size especially if you have a different alternator. (It's not the alternators fault, poor thing. )
Have you measured what you need?
This may (or may not!) help: http://www.durabelt.com/beltlengthcalculator.php