My Mark has developped a vibrate on the driveline when you shift down into overdrive and accelerate a little bit, I'm thinking ...... Universals?

Where is the vibration? Is it in the steering wheel, or just the entire car? Does it feel like the car is shaking, or just the drivetrain. How long will it do it, and under what circumstances?

Like your new avi! Sorry about the car. . .

Could be trans shudder - a.k.a. time for a fluid change.

Have a look here (http://www.markviii.org/LOD2/1_2_Accumulator_paper.htm) for some info that may come in handy.

Good luck and hope this helps.

Thanks guys, I'll research... It vibrates, sometimes feels like the rear sometimes feels like the front of the tranny... thats why I thought U's but it'll vibrate for a few seconds and.or I'll let off the gas to get it go away... it happens very sporadically and doesn't really happen at all if you drive on it HARDER... driving lightly causes it most of the time... as I think about it, more like driveshaft vibration, but its' getting rough

Tommy might be right; when was the transmission last serviced? How many miles are on it?

Whats the mileage? Im guessing od is going or the converter.

I'm at 75000 exactly last night, really think it's "just" a tune up? That would be great... I do think it drags first gear a little bit too, the car definately performs better under high performance, I notice it all when driving nicely. You guys are a great help! :yourock:
by the way.. when the vibration is "bad" the speedo bounces up and down by about 2 or 3 miles an hour from wherever it should be!