Driveshaft angle help

hello. i am getting driveshaft vibes. and premature ujoint failure. i have measured my angles and i need some help on what needs to be done.

from front to back :

without carrier bearing drop : 3.5 1.0 1.0

with carrier bearing drop : 5.6 .6 .3

do i need a shim in the rear axle? and keep or remove center drop? thanks!

 

Does your vibration coincide with a suspension lift installation?

 

Yes

 

Were exactly are you putting the measuring devise when doing this?

 

Machined surface. I used this video. I zero'd the angle on the flange.
https://m.youtube.com/watch?v=qVOzRvtn9wI&t=174s&pp=2AGuAZACAQ==

 

The only thing I may have messed up is I lifted my truck with a jack at the rear to get the tires up so I could rotate the shaft..

 

Rewatching that video, I need to add the front and middle angle, and it should be within .5 degree of the rear angle? If that's the case, without the drop, I got 4.5 in the front and 1.0 in the back. I need a 3 degree shim?

 

I added a 3° shim to mine, and it helped a little bit, but only with some of the higher speed vibrations. The takeoff vibes remain. Took it to a driveline shop that confirmed everything was balanced and aligned correctly, so the takeoff vibes are coming from something else.

 

Did this twice with a digital Klein and it did read differently if you flipped the Klein.But it all looked to pan out to .4 difference.
2.25 lift front
2.25 rear
No carrier shims.
Dclb

 

Which u joint I’ll assume the rear. Add a 2* shim under the rear leafs. That where I’d start. Simple general rule of thumb 1* per inch of lift for the shim and the angles should be equal and opposite of each other.