1. BMW only replaces transmissions- they do not fix them. They do not troubleshoot down to internal components. The ONLY solution from a BMW dealer is 'replace'.
2. Did you search here for info? There are hundreds of posts about this...
http://www.xoutpost.com/bmw-sav-foru...tml#post822944
http://www.xoutpost.com/bmw-sav-foru...on-issues.html
The short answer is this: trannys are complex; you will likely need to find an expert to do a proper troubleshooting/diagnosis; you will likely not find EXACTLY the answer on the forum; you need to not use the BMW dealer.
GL
A