Thmsabear, yes the universal u-joints do work. I replaced both on our 2002 RX300 about 1 1/2 years ago. Stopped the vibration. We have put about 15K miles on them since the repair. I purchased the u-joints from a company out of Rockford, IL.
In our case, the vibration started after the timing belt and water pump was changed. The engine had to be raised to reach some of the bolts. This caused the problem with the u-joint.
Don't waste your money on a new driveshaft. Lexus will tell you that you can't replace the u-joints, that they are staked-in. "Not True"
Go to: rockforddriveline.com There is a You Tube video about staked in u-joints. Do a search for: "Staked-in u-joint replacement" posted by bootsnthejeep.
Hope this helps,
Bill
