Wobble-1996 Dodge Caravan SE 154,000 miles

I have a 1996 Dodge Caravan ES that we bought new and I dearly love. It's just lately developed a "wobble" in the front end that you can feel in the seats, more than in the steering wheel. I happens on acceleration, only and You felt it at 30 mph and it smoothed out at 40 mph. We've tried: new tires, rotating tires; 2 alignments; CV joints, struts. Today, at a different place, up on the hoist they made the tires spin 32mph and you could see the right front tire shaking and the right trans axle appeared to be "bent". He rotated the tires again, replaced BOTH trans axles (both had already been replaced in 2001); and checked the alignment (it was ok). $451.00 later, the "wobble" hits at 35 mph and smooths out at 42 mph. It's about 10% better. Now what? Engine mounts? "Master mechanic" says mounts look ok to him and that the "vibration?" Of the engine doesn't appear to be more than normal. Please give me some good suggestions! Thanks