Thanks for your explanation. I have no doubt that our IMS industry experts have found the solution and that is; installing a big-arse-bullet-proof-bearing in place of the oem $20 NSK one.
You are spot on by saying that I have no field data nor experience in the matter. All I'm saying (speculating if you prefer) is based on common (general?) knowledge of rotor dynamics and shaft design/performance under torque and angular velocity.
A two-piece pressed fitted shaft (I think) + chains noise, seeing torque curves in the 1,000~5000rpm range?!? Castrol Gold Series Oil or not, if that shaft is not 99.9% precisely running true and balanced under these conditions, I guaranty you its end sides' bearing
will fail prematurely. Well known, proven, any engineers would confirm this to you. Toss those bearings as many oil and grease as you want man, it just won't fix it - soon or later they'll eventually explode! I'm repeating this again: "explode".
^ and that is the reason why e.g. AMG, Lamborghini, Ferrari, etc, only utilize one-piece-machined shafts in their engines and run laser precision run-out/TIR + tests on those prior sealing this in their cases. Oh and I'm sure Rolls Royce (Boeing) does the same also, do fly with confidence LOL
The only chance you and I have in a cheap-production engineering problem like this one is to do what your experts recommends: installing a big-arse-bullet-proof-bearing and the problem is so-called solved
But like you said, what do I know! Its a Porsche we drive so all that is unimaginable, right?
