Vibration felt on rear axle

[hutch424]

Hello,

Hoping for some help.  I recently bought a 2017 silverado 1500, 5.3l, 4x4, rear is 12bolt 3.08.

I seem to have some vibration coming from my seat and center console, nothing at the steering wheel.  I had the road force balance 3 times and 3 alignments in the last 2 weeks everything is checking out good.  Its been in the shop and they keep saying tires need balance, which is why I've had it balanced so many times, all the times check out good, and chevy says its within specs.  But I'm not giving up on it,  I removed the wheels and brakes from the rear axle and ran it up to speed, and I feel the vibration at the ends of each side if the axle and traveling up thru the leaf springs.  What I noticed is hubs seems to be centered and looking good but the out edge of the plate with the lugs is not machined perfectly round, did know if that's normal.

Anyways trying to see what ti check next to see if i can pin the exact spot the vibration is coming from.

Thanks in advance

I also want to add this is only small amount of vibration, and only felt at 70 plus mph.  

Thinking of putting better cab mounts in, but not sure if that is going to really solve the problem.

Edited September 14, 2020 by hutch424
updated and added info to help