Driveline Vibrations ugghhhh!

[Danger_Dave]

Hey guys. I hate to start yet another fixit thread but i could really use a second opinion. 97 3.0 supercab 2wd (2 piece shaft)

When i first got the truck with 117k it ran smooth as butter. But after putting another 50k the ujoints froze and i started getting some vibration at highway speeds. It has seen many jersey winters. I kept on driving it the way it is due to being overworked everyday and not having the time. I finally got it balanced by a shop, But the vibration would not go away, and it has been getting worse. I got it balanced again by a different shop, still no good. I even replaced the center support bearing.

So now i found a replacement from a junkyard that has low miles and in real nice shape, still no improvement whatsoever! Is it possible i damaged the bushings or bearings in the transmission or have some type of other issue going on since i drove it so long with it vibrating and shaking the whole truck so bad?

 

[Yosh1898]

Stupid question but, when is the last time you balanced and rotated tires?

 

[9050lx]

Are there any dabs of paint on the tail of the driveshaft and the pinion flange?You could try to clock the driveshaft to flange differently(90degrees at a time)U-joints are all new?Transmission tailshaft bushings OK?What about transmission mounts?They are probably junk from the vibration.

 

[Danger_Dave]

Thanks guys,
With jersey as chaotic as it is if you get a flat tire it can cause a catastrophic accident, and if youre lucky enough to be able to pull over there usually is little or no shoulder.
So the tires have all been replaced and balanced 6 months ago.
I have tried every position on that pinion flange and it doesnt seem to matter. I have also verified it is not bent. I drove it messed up for awhile so that is my suspicion perhaps the trans has suffered.