Vibration During Acceleration from Front drive

[SRacin]

Hi All,

I have googled the hell out of this and still struggling to get a solid consensus on what the issues is or what next to diagnose. So here is the summary;

2004 e53 4.8is 147,000ks (about 90k Miles)
Issues.

1. Under light to medium acceleration there is a vibration which results in a rumbling noise coming from the front and through the floor pan.
2. Harsh 2-1 shift.
3. Sometimes the transmission forgets to shift under light acceleration, rather than a normal 2k ish shift it will go all the way to 4-5k rpm.

Pulling Fuse 46 for the x-drive (which causes lots of warning lights) disables the transfer case and the noise is no longer apparent. Thus isolating it to something to do with the front drive system.

Looking back through receipts from the previous owner it appears they have had a garage try to fix this before. In trying to diagnose they have;

-Replaced the chain in the transfer box.
-Replace the driveshaft roller bearings and center bearings. (unclear if front or rear)
-Replaced transfer box oil with VTG oil.
-Wheels balanced, Alignment done. Tyres all near new. Front right lower arm replaced by wheel alignment shop.

Supposedly the transmission has also had an expensive rebuild also, but I am waiting on the transmission shop to share details of this. They said due to privacy they had to consult the previous owner before releasing details.

After many hours of googling I discovered this site;

Everything about your ZF 6HP26, 6HP19, 6HP28 transmission issues | BMW LOGIC7

This site eludes to the issue possibly being relate to the front flex Guibo joint.
The engine does not appear to rock around with rpm so not thinking it is engine mount related.

Couldn't really see the condition of the front flex disc to inspect with out removal. Figure if I am going to take it out to inspect I may as well replace it.

Any other suggestions or consensus on diagnosis or where else to look?