93 crown vic with aod trans going into overdrive sounds like you're going over a rumble strip for a second then stops?

Answer 1

Some years of Crown Vics (and Grand Marquis's) develop a torque convertor "shudder" problem. The symptoms are very much like what you describe. It can often be fixed by doing a full flush of the transmission; a FULL flush; not just changing the transmission fluid and filter. The transmission has a lot of fluid in it that does not drain during a normal transmission service so you need to get a full flush at a shop that has the proper equipment to do it (some better-equipped oil change places can do it if you trust them to do so). If it only exhibits the symptoms when shifting to overdrive (and not when shifting from 1st to 2nd, 2nd to 3rd, etc.) it may be caused by something other than the torque convertor issue described above. There can also be an issue with the overdrive solenoid not engaging as it should and causing a shudder when the car shifts into overdrive. I don't know what years this affects or how hard (or expensive) it is to repair. Just be aware that if this is an "overdrive-only" shudder it may be the solenoid or some other component related to the overdrive system and not the torque convertor problem described above.