Could a u joint be bad and show no signs of being bad? Here is the situation, it is on a 1 ton Highangle shaft. I put the truck together, it drove fine with no vibes all the way to 80mph. I put almost 1000 miles on it before it's first wheeling trip. Wheeled it on a Saturday on milder trails but only in 2wd because of steering issues. There were quite a few times I should have used all 4 wheels but used the stupid pedal instead to get through. Well we left that Sat. and I noticed a bad vibe and chacked it out back at camp and found my t case mount was loose. I tightened it up and it seemed ok on Sunday morning when we hit the interstate to head to the 2nd day of wheeling. Well the more we drove the worse the vibe got so I parked it for Sunday and hitched rides for the day. Drove home vibrating pretty bad around 55mph on up. Now fast forward a few weeks to now and I finally start working on it. I pulled the rear shaft and took it for a drive on the front axle and it seemed ok up to 55mph and no really bad vibes, only problem is the Powerlock in the front is a bitch to steer without hydro assist. (Got the WTO stuff, just need to install) So I pull back in the driveway lock the e brake and do a nice smokey burn out on the front axle. Everything seems fine there. I look over the rear shaft really good and it all seems fine and there is no slop in the rear pinion. Could the u joint be shot and show no real sing of being bad?