Ok, here I go again. Heh. At about 25-30mph on my 93.. I can hear a rumble/vibration coming from under the car (or at least thats where it sounds like its coming from). Anyone have any idea what this could be?

Man, that could be A LOT of things. Is there anything else you can do to define the problem that might help us narrow it down? Does it happen between 25-30mph regardless of RPM, or if you downshift manually does it go away?

it doesn't seem to matter about the RPM rate.. But, usually the car is driven normally when i hear it.

probably vibrations from your driveshaft

Transmission shudder maybe?

vibration from the driveshaft sounds like it would be it... what do you recommend?

vibration from the driveshaft sounds like it would be it... what do you recommend?

I hesitate to diagnose sounds over the internet :Bang , but...

Since you have the '93, if it is the driveshaft it is most likely the universal joints since you have the coveted one piece driveshaft(assuming no physical damage to the driveshaft). If you elect to do the work yourself, be sure to match mark the pinion flange before removal so integral balance with the rear is maintained.

I went throught this on my Mark... Unfortunately you have a shudder. One of those $99 Aamco Transmission Fluid Flushes (Torque Converter Inclusive) MAY, MAY Resolve this issue. (If it ONLY STARTED happening.)

However I needed a Torque Converter and Output shaft... I opted for a complete Transmission

Take it out of OVERDRIVE. If the shudder only shows up in O/D, then you can take my opinion to the bank.

Lucas Trans Fluid Treatment might help as well. Just add a quart -