Truck vibrates/shakes when fuel tanks are low on fuel

No. Harmonic balancer is still good. If i had isssue it would be vibration rpm related but this is more mph with acceleration.
From same guy that i bought this 99 T2000 i bought 2000 T2000 parts truck, everything minus C15, tranny and driveshaft. Truck had 250k miles and guy needed drivetrain for his glider. So frame was like brand new.
My work truck had 550k miles whrn i bought from him in good shape. I just didnt like idea of old truck with low miles. And i started replacing parts that were old. Im nuts i know i cant stand without doing something

 

Swapped two drives with wheels, one of them have weird wear, with my parts truck two tires and wheels. Took it for a spin with trailer, it still shakes.
Now im gonna pull all 3/8 spaces from swaybars bushing and see whats angle of driveshaft and test it again

 

Pulled 3/8 or 10mm spacers, while i was there installed new bolts and nuts 10.8 grade since i was messing with those bolts a few times. Since i was there geased whole truck. Driveshaft angle changed about 1°. Took it for test drive. Looka like it vibrates less.
Thing with AG200/400 suspension, it was make do contain same driveshaft angle on any height, its not like other truck, this thingbit got more bushing than 3 standard truck. Anf i replaced them all.
Next thing is to buy gopro and mount it on different sport and see where vibration is coming from

 

Today since i have valves on both tanks on feed and return i tried shut off one tank at the time and drove it for some time. No changes so its not issues in pick up tubes tubez

 

Here is funny one, i just disconnected leveling valve on sleeper and there is much less shake. Sleeper is sitting on rubber bump stops on frame. So whatever is cousing vibrations it transfer on sleeper when its on air bags and sleeper bounces. Funny thing is shocks are only a few months old original Paccar special orded $220 for two and i replaced them so i can see if its gonna bounce less but with old and new shock ii have same amount vibrations. Front cab mounts are 3 years old, rear torque looking bar under sleeper is year old. Leveling valve is 3 year old. Sleeper air bags are original but they not leaking. So there is no bad bushing anywhere
So these vibrations must coming from drives or rear of the truck ???

 

I dont know where to hunt anymore, maybe new drums on drive, or insrall my old aluminum wheels, but if wheel is bent it would show up on uneven thread on tire but all my tires have even thread wear.
I was thinkin to buy gopro but never had a chance

 

Its not fuel level, i tried low, mid and full tank doesent matter. Bobtail almost no bouncing, empty trailer and up to 30k bouncing, over 30k less. I tried spin front outside wheels with tires 180 degred, same thinv, i was gonna do rear drives but broke tire dolley and it was getting late. This thing its gotta be from drive tires, diffs or #### driveshaft. Im going nuts. From now on im hauling 45k loads only
Whatever its it makes sleeper bounce, also hood mirrors. Could be huge gap between sleeper and my dry van since i have long wheelbase truck and air gets in between ???
I replaced all yokes except on tranny anf front diff input, maybd one of them is bent. I need to buy some gopros