Rick..a carrier bearing being slightly off center will not effect vibration but is the the same as changing the up/down angle of shafts. It makes no difference if it's up/down or back and forth to the joint. It will be used on a rear end that has higher degree of C/L offset than the engineers want for total working angle. All joints should be set to cancel out the angle of the opposite end. If you didn't take the shafts apart it probably isn't your vibration problem I wasn't clear on what you meant to say about that aspect of things. It sounded as though you'd taken the rear shaft apart for rebuilding and therefore could have replaced it out of phase onto the midship stub shaft which would be a vibration problem.
Denny, ALL u-joints must be in phase with one another. Think of it this way..12 o'clock, 3 o'clock, 6 o'clock and 9 o'clock. This must be the way to smoothly transmit power regardless of the number of driveline sections, be it 1 or 4 pieces. So it really has nothing to do with "movement" or the angle degree of a joint if I follow your meaning.
Ron..if a needle bearing is in the bottom of the cup it become impossible to replace the snap ring into the yoke but I've seen guys crush them in presses attempting to do it and even bend yokes.
I fully understand the concern one has when you see off roaders, mudders, monster trucks, etc. that have very high degrees of angularity. Your correct to assume the short life of these joints. When I had the driveline shop I used to have a customer who would go to mud runs on Sunday and leave his driveshaft by my front door so I could rebuild or replace it on Monday. This is one example of how short the life of improper drivelines can be. In this case it was too much power and steep angularity. But it illustrates how critical it is to match a lot of variables to make the things work as intended.
