What does it mean when your 1998 Ford windstar shutters at 50 miles an hour?
I’d have to ride with you to know for sure, but you could have one or more of your tires that are out of balance. From your description, I doubt you have a torque converter shudder, since the lockup usually comes in around 40-45 MPH. Since it is at 50 MPH, I would think tires are your most likely culprit.
