Just an FYI for you guys with a 2-1 slam problem.
When my E53 got the problem, I did a detailed investigation as to the best fix for the problem and ended up replacing the valve body in the transmission with and after-market unit that has improved solenoids and other upgrades. Been over two years now and my transmission still shifts as smooth as butter with no service since installation. Here is a link to the unit I installed.
https://redirect.viglink.com/?format...mechatronic%2F
It cost me $600 for the install plus $1k for the unit for what appears to be a lifetime fix.
AceEngineer
