Mark VIII owners or former owners question inside

[1fast4]

I have a fairly low mileage 98 that has a driveline vibration that starts around 80 and gets worse as speed increases.
I have read numerous times the cause is most likely the driveshaft.

Have any of you experienced this? Heard about it?
How did you fix it?

I have a 1 piece out of a 93. Before I go through the trouble of swapping them, just wanted to check on here and see.

Only mods are cat back exh, cai, tune, & 4:10's.

[90MarkVII]

Look in at www.lincolnsonline.com

There is a Mark VIII forum where I bet you'll find someone with the answer.
There is also a Tech section with articles on common issues and how to fix them (nothing on drive shafts right now, though).

[JC316]

Driveshaft. Common problem with the two piece design, put the one piece in and be happy. Have fun dropping the gas tank to change it.

[1fast4]

Driveshaft. Common problem with the two piece design, put the one piece in and be happy. Have fun dropping the gas tank to change it.

Ya, that's what I've been dreading. I don't have my garage right now cause my project taking up space. And my driveway is at a slope. So doing it myself is going to be a MAJOR pita!!

[slow84lx]

My '98 has 170,000 miles on it and still does not have this problem although it is common to the '94-up Mark VIII's. I have a '93 driveshaft from my parts car in the garage also if the problem ever occurs.

I think that the 4.10 gears are contributing big time to your driveshaft vibrations.

Are you positive that there are no bent rims on your car and the tires have a good balance? The Mark VIII's are very sensitive to tire balance and will give the vibration issue you describe even if it hasn't been long since the last tire balance.

[JC316]

Ya, that's what I've been dreading. I don't have my garage right now cause my project taking up space. And my driveway is at a slope. So doing it myself is going to be a MAJOR pita!!

It's really not that bad. Just 4 bolts, then a couple of hose clamps. I just did this on my 92 Tbird super coupe. Took me all of 15 minutes to drop the tank.