Soo I am having a problem . I am doing my ex-wife a favor and working on her 97 E320 with a 722.6 tranny and have encountered some issues. After her original transmission went bad (front pump went out and kept going into limp mode) I installed a known good tranny from the wrecking yard out of the same year/model car along with a new filter and MB synthetic fluid through the dip tube using the MB fluid level tool. After installation the transmission will not shift out of 1st (or 2nd..not sure which one its in) and the check engine light light is on giving off a code of P0730. That code reads as "improper gear ratio" on the web but the dealer told me that the book just states that it indicates there are codes that need to be read in the Transmission Control Unit which I didnt read yet. I have heard different stories and do not know what to believe...one shop says I may need to have them clear the codes and initialize the software to take it out of limp mode....another says that the valve body in the new trans may be a different version than the control unit...and another said that solenoid plate or something might be bad. Like I said I am doing this as a favor for my ex because she is very short on money and couldnt afford the labor costs for the tranny install and now we are still in the same boat with no real answer on what is going on. Any ideas out there? What sounds like the likely culprit? What should I do first? BTW, when the old tranny was in it would work fine when it was cold shifting through all the gears, but once it heated up it the front pump would start grinding and then it would go into limp mode and eventually wouldnt move until it cooled off again. Now it doesnt shift at all cold or hot and it also bangs into gear when putting it into DRIVE or REVERSE.