I have a 1999 Lexus rx3000 FWD. I have 350,000 miles on it....I am one who loves to do work on my car. I replaced the Two piece CV-joint with a one piece from a 97 Toyota Camry. I did all the math and checked everything I could and it was a total match. Except that the built in Balancer was a about 5 inches bigger. I drove it for about 5 thousand miles and I developed a vibration. Not much but at about 30 miles an hour it would start and by 45 it was loud and you could actually feel it in the wheel. I drove like this for a while before I went and got an original axel (passenger side) (two piece). The vibration subsided a bit, but not entirely. I still have it. I have checked everything from Bearings (replaced 10 thousand miles, to the other CV-joint, replaced 15 thousand miles ago. I have determined it could be the tires but have not changed them yet, doing that soon. I know that my Transmission shifts a bit hard, but I recently flushed it, but no change. I also get a vibration when in drive when at a stop light, so I changed all the motor mounts (4) and it may be the torque convertor, but that should not cause the vibration I am feeling during the drive. I will update, but if anyone has any idea that would be great...