1998 Mercury Grand Marquis transmission shudder

” My 1998 Mercury Grand Marquis is acting like it needs a new transmission. When shifting at about 30mph I get a vibration like I’m driving over rumble strips. Not all the time or when I’m accelerating quickly or very slowly, but in that in between range when the car is rolling along between 30 and 40mph. Anything I can do short of going to some transmission shop and getting charged for a replacement transmission?”

Yes, there is a good thing you can try, which can help such a problem. Your problem is technically called transmission shudder. Change out the transmission fluid and filter, and install a premium synthetic transmission fluid in the car (such as Mobil 1 synthetic transmission fluid.) And also add some anti shudder additive to the mix, such as Lucas anti shudder transmission additive. Give the stuff about 450 miles of driving to work its way in. Hopefully this will help and you won’t have to pull the transmission off and have it rebuilt or replaced. I’ve seen such a process work wonders.