Simply this: these are counterfeit. Not made by, or for Porsche.... they have a group of folks who do nothing except find and point out this type of product.

The failed sprockets were sent back to Sebro, and they were tested for harness. If they were counterfeit, they definitely would have mentioned it.

The sprocket in my pic is from Porsche. I doubt they were sold counterfeit sprockets either.

Tyson, I really appreciate you (and Henry) bringing this to our attention. It's access to professional opinions like yours that make this forum great!!

Don't you hate it when you answer a question then it just leads to more questions??? Sorry to ask but there's a lot to know......

Has there been more than one actual failure?

Was it an intermediate sprocket or cam sprocket, both, all four, or all 6?

Is the date of manufacture of the failed parts known?

Is the part # and revision of the part(s) known?

Did the returned parts pass or fail Sebro's test?

Can we see pics?

I'm following the breadcrumbs here, trying to decide what to do with the short block in front of me. I have faith in my cam and idler sprockets, having tested them for hardness, but the intermediate shaft is sealed up in the case.

To make it more interesting, the cam sprockets that I tested for hardness were revision 02 parts, yours look like 04 parts, and the ones buried in my motor are 04 parts as well.

It is a problem on all the sprockets. Cam, tensioner and intermediate shaft.
Parts affected started at 10/2017
Sebro passed the failed parts by their hardness test, and denied warranty.

New parts tested higher on the Rockwell scale than the old parts, so that can't be the issue.

Not seeing how they could be from Porsche. No JP triangle or whatever they call their authenticating logo.....

This strikes me as really odd. Especially considering it's the idlers too. In relative terms they have very little load on them.

Are we talking about multiple instances or an isolated incident?

If it's not the hardness, maybe it's something with the pitch, increasing the point load on individual chain rollers or something like that.

Maybe even a problem with the chains "taking out" the sprockets?

Still wondering, how many failures?

I bought them around 2012-2013 hopefully they're OK?
From our host, they weren't sebro IIRC.

Not sure how many, but multiple failures across multiple shops.

Mark, you should be fine. Parts numbers traced to late 2017 batch.

I'm the guy doing the rebuild with Forssling. Making a few Youtube-videos of the rebuild. If you are interested in watching us doing our first Porsche rebuild, watch, like, subscribe etc. You know the drill. :)

https://www.youtube.com/channel/UCuWGubdchPUxqA_TFEY36Lg