I've been fighting some vibration problems on my 1997 Cruiser (its in an older thread). Today I took my front driveshaft to a driveshaft shop that's fairly reputable for balancing. The guy noticed two u-joint caps were rotating in their yokes. Specifically one in the sleeve yoke (front piece of the shaft) and one in the flange yoke (rear piece that attaches to the transfer case). It was very appearant as he rotated the u-joints. Both the caps are in line with each other, which makes me go hmmm. He asked where I bought the U-joints (CDan) when I told him they only have a couple thousand miles on them. He said since they were Toyota (they've had problems with other brands) they should be fine. All of this led him to tell me that I need to replace the sleeve yoke (if I can get it) and the flange yoke but the U-joints themselves are probably still okay. He said it's very unusual to see this on a Toyota since their stuff usually lasts. The truck had 102k miles on it when I replaced the U-joints. The old U-joints were pretty dry and one had a small hitch in its rotation, but they didn't seem that bad (proabably never greased before I got to it at 90k miles). Assuming I didn't butcher the installation job too bad (everything seemed to go okay), what would cause this? The fact that the caps that rotate are aligned makes me suspicious. I don't want to replace everyting to find out that something else in the vehicle is causing the wear (seems unlikely). For the record, I still have a vibration at 55 mph with the front shaft removed but its significantly reduced (rear shaft as well?).