I have a 1998 mercury grand Marquis with about 146,000. I get to 50-55 and have a vibration. thought it was torque converter shudder, but flushed the tranny and changed the filter to no avail. any ide
Is the CEL on? Any codes? Balanced the tires lately?
If you do have converter shutter servicing won't really help, I have had some luck using a product called Shutter Stop, you just add it to the transmission fluid, it really worked on my old Bronco, had to put some more back in after I serviced it as the shutter came back without it, was still working when it got wrecked. Advanced auto parts use to carry it.
CEL? Also, I have used shudder stop but it didn't work. I'm not sure it is shudder, but it feels like running over rumble strips.
That sounds different that converter shutter, you may have an internal pressure problem or solenoid chatter inside the tranny, have you had it too a tranny shop for any tests?
Looking for a Used Grand Marquis in your area?
CarGurus has 1,706 nationwide Grand Marquis listings starting at $1,700.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts