My BMW X5 2003 3.0 81K

driven gently! (that hasn't helped as far as overall reliability,
wish I had my old beat up Jeep)

All right so I feel like an executive in my Beamer!

noise is coming from transfer case or with a few inches of there,

sounds like if the brake pads were touching metal

no grinding, no tac tac tac

oil is full.

I probably have the earlier version on transfer case NV something

only happens during acceleration !

starts at 5 mph and up to 30-40 mph,
sometimes loud sometimes much softer

can this be a stretched chain !

Its going to be a DIY project since I cant a$$$$$$$=ford
the price tag, I will even rebuild the thing if I have to,