2007 328i 6 speed

[Kyle]

I have a 328i 6 speed automatic with 70k. Engine runs strong.
Vibrating/shuddering occurring when I drive. Occurs when I hit the gas and the car shifts down. Occurs in both D and DS modes. I took it to the dealer who said they would have to open a PUMA case to further analyze the problem as no codes were displaying. I decided to take it to a friend who deals in BMWs. After a test drive he thought it might be the driveline/u joints. After removing the driveline and inspecting it it seems fine. I dont want to buy a transmission and find out its not the issue. Any suggestions on what it might be or ways to troubleshoot this? Thanks

[Kyle]

oh I should mention that I have been driving the car like this for a while. I can even put it on cruise control on the freeway and it will be smooth for a while but when it needs to shift gears (3-4-5) a noticeable shuddering/vibrating occurs.

[HBWT]

ALWAYS a transmission issue based on my experience. This is especially true if the vibration & shuddering are not accompanied by some kind of noise. Has the fluid ever been changed? FWIW, the fluid in my 335 will be changed at 30K...same as my E46s. I pay for it and expect it to increase the life of the tranny. Whether your problem is hardware or software is anyones guess until it's looked at. I recently had my tranny(ZF) software updated and it profoundly improved the way my car shifted under hard accelleration(downshifts). The software corrected a fault with the torque converter lock-up. Supoposedly this fault was discussed in Roundel Tech-talk but I must have missed it. GL.

<a href="http://s131.photobucket.com/albums/p315/hoscarnag/roadflypix/?action=view¤t=335siggy.jpg" target="_blank"><img src="http://i131.photobucket.com/albums/p315/hoscarnag/roadflypix/335siggy.jpg" border="0" alt="Photobucket"></a>
2008 335i Coupe Alpine PP SP CWP Saddle Heated Seats Comfort Access Sirius iPod PS2s(non-RF!)