vibration/drone sound at high speed

[vtx1800sba]

Ok guys I'm still experiencing a vibration/drone sound in my 96 two door at speeds over 60-65mph. I just had the u joints replaced yesterday on both driveshafts. Rechecked the rear shaft; made sure both u joints were properly greased. stay bolts tight on yoke. WTF? I notice it gets pretty loud at about 70mph then drops off a bit at 75mph.

Not sure what to do. I had my guys clock the yoke on the rear diff, 180 deg. to see if that makes a difference. It didn't. I did find the roof rack slide bars were loose. In fact the rear one slid pretty easy. I notice the screws under each end of the bar are backed out a ways so the bars can wiggle up and down a bit. Tightened up the bar slide bolts will get those screws tomorrow.

Any thoughts?

 

[vtx1800sba]

Mystery solved. The rear most u joint was the issue. One of the joint caps was sticking out of the yoke on the driveshaft. Had not been seated in as far as it should have been. The clip was able to be fastened. Once we swapped out that u joint for another new one, and paid attention, no more vibration like it was. Seems to be just a little at around 75mph. But maybe that has something to do with all new u joints front to back.