Driveline vibration

I have thought that. But the only way the angle could have changed is the new bearing rubber supporting it up higher now. Unless the vibe was there before and disappeared after the rubber went to crap. Too much time has passed for anyone to be able to remember that.
Man. You got me thinking about that.
I think for experiment reasons cut a 1/4 plate drill some mounting bolt holes and sandwich it between the top of the bearing and the mount on the cross member and bring it down to about were it was sitting when bad and see if it clears up.
This truck did have a 4 speed brownie box and it was removed 25 or so years ago and the center bearing was put in its place so very likely the dangle angle ain’t perfect.

 

Finally went thru everything yesterday. Ran bobtail Friday morning (first good dry non rainy day in a week down here) and ruled the trailer out as the cause. But I noticed it had a slight howl in the front box in low side gears that wasn’t there before. Grrrr! Jacked up all the corners Friday afternoon and ran it thru the gears and let it run in 7th dir and od in the air. Nothing seemed out of the ordinary. I then started at the rear and worked my way forward. Checked everything from suspension to frame and greased everything again and everything looks solid. Shook all the yokes and no movement. Tires are rolling good. Re adjusted brakes for the heck of it since it was up in the air and the wheels were free.
After a few hours I noticed one little drip of oil under the output of tranny on the floor. ( never leaked before). It was coming out of the yoke at the nut and not the seal. I spayed it with brake clean to dry it out. The nut looked tight but when I lightly turned it back and forth you could see a miniscule bubble of oil come out with the help of a bright light between the nut and washer. I marked and tightened the nut. It only needed a 1/3 turn. That isn’t much on a fine tread.
Test drove this morning and noise and vibe free!
Did not seem to be that loose to cause that type of vibe but I guess it was more sensitive than I would have guessed.