X5 shaking badly when accelerating on low speeds

[gogz2005]

Greetings all,
I been having an issue with my 2002 X5 for few months and I been to at least 8 different shops and no one could tell me what is wrong.
The problem is that the vehicle shakes very badly on speeds between 20-30 MPH especially if I am going uphill. It also shakes on other speeds but most noticeably between 20-30 MPH. When I try to accelerate steadily between those speeds the whole front end shakes. When I release the throttle or accelerate faster the shaking will decrease quickly.

I changed the left front axle, drive shaft, transfer case and the transmission fluid right before this started happening.

I also did the following trying to fix it but no success:

Changed the right front axle.
Changed all front control arms.
Changed sub frame bushings.
Nothing seems to fix it and even BMW Dealers can’t find the issue.
Any suggestions? I’m getting so sick of chasing down this issue.
Thanks in advance guys.