Weird vibration 02 tb

Hello,
weird vibration from my 02 tb started slowly and rarely since a few months. First starting after a stop for a few seconds, now more and more until it makes a boring noise driving the car. I can also feeling it under my feet and on the steering wheel, no matter if moving the car or just pushing the gas pedal while in "P", same issue. Fan clutch is fine, I recognize that noise but this is different, more heavy as if crankshaft would be out of balance.. No good at all. Suggestions?
Thanks
Ps: I want my old 95 grand cherokee back!!! :iceslolan

Very tough to help with this on the I'net, disconnect the serp belt, see if there is a difference, check all the exhaustt shields and pipes for grounding to the body.

You're right about the difficulty to answer about a vibration on internet! I just changed oil to all three diffs and nothing changed, but no grinding inside at least. Now I want check exaust manifolds, clamps, covers, whatever can be broken or loosen.

After a few time driving with new oil in diffs, vibration desappeared as it came. Can somebody guess an answer? I don't believe in miracles, maybe something was working bad with low/old oil in diffs? Even auto 4 wheels drive wasn't working properly..
Thanks