My 2008 Taco 4x4 had a vibration on initial acceleration, and mechanic I know said I needed a center support bearing. I took it to a shop I trusted and they said I needed a U-joint as well, and that it would be a "serviceable" one. I got the truck back, and as soon as I gave it gas is shuddered badly, as well as the original vibration. I took it from the shop (I don't trust them any more) and a friend and I figured out that it makes the noise in 2wd, but not in either 4H or 4Lo. Other than that we're stumped. Everything is tight down there. Any help is appreciated, thanks!