Rear end vibes on takeoff after lift

I put Coachbuilder 3” shackles on my 2020 pro with 3/4 cb drop and rear vibes like crazy on take off. I’ve taken the drop spacer off added washers and taken away with no help. Any ideas?

 

The +3 shackles are 1.75" of lift and the carrier bearing spacer kit is for 0-2 inches so you shouldn't have any vibes. Did you torque them to 25 ft lbs with the truck on the ground?

 

Yes sir. That was the first thing I did after speaking with David. I had all new bfg ko2 at the time of lift install- thought it may be them, so I rotated and rebalanced to no avail

 

Hmmmm....and it's a pretty simple install.

 

Yea. The install is simple.

 

Your driveline geometry is not happy. Sounds like carrier bearing is pissed off.