Truck vibrates/shakes when fuel tanks are low on fuel

Truck probably

 

Ok. Friend of mine have different trailer than last time. This time is same trailer as mine Wabash dry van with Hendrickson Vantraax just 2018. Both have kingpin 35" from front edge of trailer. His trailer doesnt bounce at all. Than i took his 2011 Volvo and hook my trailer and took for 20 mile test ride. His truck bounce with my trailer but not as much. He was with me and said he can feel it too.
So i checked tire runout on my trailer and also on my truck with nice magnetic holder and dial indicator. Truck tires was in 30k runout. Trailer 50k runout. So its not tires. I did notice hub/wheels on front axle left side was little harder to turn when breake are released but not much. I may take hub off and check bearing, may need bearing adjustment
Also i read this thread trailer brakes locking up/ hopping post #8 guy said maybe Hendrickson Surelok maybe causing uneven air in airbags front vs rear. I did same problem like that guy in that thread with axle bouncing when breaking but it was like 3 years ago but in that time i had 04 Volvo and that axle bouncing stoppet for no reason. Year later i sold Volvo and bought this T2000. I may check those Sureloks

 

I think its my trailer. Doesnt do all the time. It have to be tires. I think trailer tires or suspension vibrate and than transfer vibration to the truck. Since i have Atro poly bushings on every possible place on my truck it vibrates even more since poly bushings are stiffer than OEM rubber bushings. My vibrations started when i installed poly bushings on drive axles. I may switch back to OEM rubber bushings

 

I just did Atro bronze kingpins and vibration is still there. I dont have any more bushings or mounts to replace, every single one is new on truck. I checked trailer bushings and they still good. Trailer is Wabash 2016 dry wan that i bought new. I installed new Hendrickson shocks, S cams, brake chambers, 2 leaking airbags, drums and brakes, hub seals, even got Centramatic ballancers on trailer. All i Alcoa new aluminum wherls and good tires. Only thing thats left is suspension bushings, 2 airbags, air valves and ABS module

 

Update
8nstalled new OEM Paccar rubber bushing in sway bars. 3 year old blue Atro had some play. OEM rubber bushings didnt fixed vibration. Next is
New steer axle hubs
Maybe new drive shocks
Oem Rubber carrier bearings, right now i have blew Atro
Im loosing my mind over this, is it possible this is because i have Ag400 suspension and long wheelbase truck, 32" longer than standard T2000 ???

 

New steet hubs , didnt fix vibration. Next is new drive axle shocks, 3 year old black monroe HD need to go. Going back to paccar again
A few months back i drive bobtaul for about 300 miles. It does vibrate with bobtail but not much. I can feel it. So its not trailer. But witj empty trailer and footnon accelator will vibrate. Heavier load less vibration. Im thinkin maybe something in power devider. Last december when local KW reseal both diffs didnt say anything was worn out inside
I dont know. I wish whatever its just blow up so i know what to fix it