Truck vibrates/shakes when fuel tanks are low on fuel

New drive shocks didnt fix vibration. Now matter how much fuel i have in tanks it will vibrate. Looks like little less vibration on heavyer load, and less vibration up hill. Also almost all vibration goes away when i lift fuel pedal. I tryed shut of truck doing 65 in gear and in neutral, vibration is still there but not much. But iilf i fly over big bump or vhen ag400 suspension exttends for a second vibration stops. Its veird
I installed all new fuel lines pick up and return but didnt mess with tubes in tank. This truck csme with two 100 gal tans and i swap them for two 120 gal tanks from my 2000 T2000 parts truck that had 250k miles on chassis

Im thinking yoke on tranny is still original and i have new tranny and vibration stated before installing new tranny so maybe yoke is bent ? I did see little bit oil lead on rear transmission even CIT fixed that leak once. Also all driveshafts a4e bsllanced twice. Even small one between front and rear diffs. Maybe driveshft angle/pinion angle is off becsuse this is long frame truck and going from ag200 to ag400 that i got from standard wheel base part truck. Cit adjusted alightment but didnt check pinion angle
Also my steer shock doesnt last long before they start leaking oil of they broke on weld from all front end bouncing

Im going nuts. And i dont want swap ALL parts from this long WB truck to my standard WB truck. Too much work. Even i coulf get better mpg because of huge gap between sleeper and dry wan but than i wont be longer than 379 or W900s lol

 

Well drive drums were replaced when i bought truck in 2018 before vibration started. Truck came with short wheel studs that are ment to use expensive centerfuse ballanced drums. I may look into new drums. A few ago i did go back and installled longer drive studs so i can use standard brake drums. Im using true ballance sleves snd centermatics on drives too but that didnt helped with vibtation
What it gets me why almost no vibration on bobtail bus as soon i hook trailer vibration starts
One other thing around same time vibration start i installed Ali Arc big heavy bumper guard. But i dont see why that would vibrate more when i hit fuel pedal or jake brake. Or maybe it does. I didnt try ren it without it. But this thing must be rotation vibration. It starts around 58 and fasteer i go it vibrate/bounde front of truck faster. At 85 almost goes away

 

Ride height checked 50 times. Tried lowering and raising height, same thing. Changed valve 4 times. Changed splitter/feed valve, that feed air bags, all hoses, all 8 air bags
Driveshaft was ballanced twice and fixed by freightliner and guy told me to line up evetything and he left marks to phase
While chasing all these vibrations truck is like new now. All parts new. I could buy brand new truck for money i spend but it wouldnt be eld free lol

 

I measured my diveshaft behind 1st carrier bearing. Its 0.4° slope going town toward 1st diff
Driveshaft behind 2nd carrier bearing is 0.8 ° slope down
Small driveshaft between diffis 7.2° toward rear diff
I found ranfim T2000 with different suspension but hey why not take look
He have standard sleeper truck so only one carrier bearing
Driveshaft behing carrier bearing was at 0.5° slope toward 1st diff
Driveshaft between diffs was at 5.8° slope toward rear diff
I also measure my original AG200 contol arm and its same ar new AG400 swaybar so its not any longer or shirter since there is 52 and 54" axle spacing AG400. And my is 52" so im good.
I ghinknif i take 3/8 bushing spacers from swaybar i may lose both front and rear driveshaft angle. Dont know how much till i do it

Also i may swap a few tires/wheels with my parts truck old junkers and see if vibration stops
Also new cast drive axle drums if price is right, but looks like thay are $120 each compared 2 years ago $80 each

 

What damper ??

No i didnt stretch this truck i bought this way 4 years ago from company that hauls Nascar race cars. I think KW build it with long wheel base. Frame is in one piece. Truck came with two 100 gal tanks and i installed two 120 gal tanks from my standard WB parts truck. I pulled them back as much i could. When im at 80k im at 12k on steers so im good. I tried 3 different steer shocks but same thing