Timing Chain Tensioner V6 TDI AKN

Hi,
I'm experiencing a strange noise, accompanied by jerking, which may be related to the belt drive.
According to a technical article, the standard pulley of the alternator in the AFB (which is now very similar to the AKN) should be replaced with a pulley that includes a freewheel mechanism.
Part number for Valeo: 028 903 119Ac. My parts supplier listed it as 022 903 119b.
"This disc doesn't quite fit in terms of diameter; it's 55 mm instead of the original 64 mm, and it's also narrower, about 21.5 mm instead of 23 mm. Did my dealer make a mistake, or does the specification only apply to AFB models and not AKN models? Or is it even completely wrong, and does the '028...' designation refer to AFN models, as I found on Autoteile.cc?"

You can't just exchange things like that so easily.
You need to provide more specific information about the vehicle. Also, it would be best to identify the alternator manufacturer (Bosch? Valeo?) and its amperage rating. Ideally, please provide the part number.

Hi,
Valeo 120A, the part number is only visible if you take it apart, which is a clever design. There was also space for a sticker on the bottom.

/viewtopic.php?t=3687&highlight=pulley+image
Here is the relevant section from the article.