I lost 3 u joints and the carrier at about 45k. When the left I experience heavy vibration from 40 mph to stop. One of the u joints had froze up also, so that would have increased my vibration dramatically.
This was my first trip to the dealer since new and surprisingly enough they covered it under warranty, Good dealer (I bought my wifes 4 runner from them also that probably helped). They did a full driveline replacement vs changing all u joint and carrier which I thought was good at the time but now my rear seal in the t-case is leaking a little, oh well a seal is a heck of alot cheaper than the u joints.