Just saw this thread as another lister mentioned it in response to a leaking upper that I found on a new UCA.
I have to say that if mine is bad that I think it to be a fluke. These things are just beautiful. Now what do I know, I haven't even driven it yet. But I had been wanting to invest in a set of these for 6 years.

I think if it a failed seal, I am tempted to drill and tap for a grease fitting and call it a day. From the engine with a bad cylinder to, a repetitive failed ECU last week and now this, I think the 928 world is helping me decide how to downsize.