Gotcha, that makes sense then. So tuned, we'd be up around where the stock 535d is, which should be safe if you're not on max boost 100% of the time (pushing the limit).

 

Yes, the huge diesel NMs are responsible for blowing the transfer cases, not the HPs. I mentioned the HPs as an indicator for the power increase.

And yes, the F10 has a much stronger transfer case.

I should also mention that the guys that blew theirs on E60s were experimenting a bit with remaps and 0-60 times, so the stress on the cars was quite intense. One also damaged his differential, which is also rare otherwise.

 

I took my car to the dealer today for an oil change.
in addition i asked the service consultant to check on a humming sound that just developed the moment the car start rolling.
60 minutes later it was diagnosis revealed the beginning of a failing transfer case.
Repair cost US$2700 + 6% TAX.
Luckily I have an after market warranty who's covers this, and Just about everything; similar to a dealer dumped to bumper warranty.
My deductible is US$200
Needless to say I was relief to know this was a covered component as it is considered part of the drivetrain.
The sound starts out like a "whom, whom, whoom" rhythm and could be heard at all speeds.
Its been only 2 days experiencing the sound before taking it to the dealer, so I don't know if it would change, or cause something else to fail.

I should have the car back by Feb, 4th. I will update this post accordingly.

 

Did you purchase the car recently or have you had it for awhile? The reason I ask is if you've owned it for awhile, YOU may be the reason the transfer case failed. Are you aware that on AWD BMWs, you need to make sure the rolling circumference on all four of your tires is the same? If you have a staggered setup, this may not be the case.

 

It's been a little over a year since I own the car. Prior owner could have used different tires.
I will know more when the BMW technician follow up with me later this week