Happy Thanksgiving one and all. I am trying to get an image in my mind as to how to go about checking to see if a driveline is in phase. My earlier post about the severe vibration since restoring my '53 3/4ton leads me to believe that the problem is with the driveline being out of phase. It is all installed, so what's the easiest way to check it? Is it possible to check without dismantling the driveline? I'm curious as well what specifically needs to be in phase. I never changed the driveline, but I did remove it and tore it down. All new u-joints and seals. This truck has the two-piece driveline with the front section enclosed and a carrier bearing in the center. Am I correct in assuming nothing needs to be in-phase forward of the carrier bearing? The shop manual talks about making sure the front of the rear section of the driveline is in phase with the tail end of the rear section. I did not remove the portion of the driveline that slides to compensate for movement in the truck. I'm not sure if that is splined inside or not. Any help with phasing the driveline would be appreciated. The manual does a poor job of explaining it and when I tried searching for previous posts, I keep getting a message that indicates the page is expired. I have to start the search all over each time I look at one individual post. thanks in advance for any help.