Just aquired a 91 740 w auto trans, PO said that car would not go into O/D. He thought it was the O/D solenoid. I ordered a new solenoid, but while waiting for new part, pulled the old solenoid, and tested to see if the plunger worked. It didnt, but while I had it out, remembered the old O/D elimination trick, by making a channel in the solenoid face. When I put the old solenoid back in, still wont go into O/D. Questions 1. Should I flush the trans before installing the new solenoid?2. Im thinking that if the old modified solenoid didnt work, will the new one work?. Thanks for any help you can offer.