Vibration problem 30mph-55 mph only

My pickup has started to vibrate when I am accelerating 30mph- 50 mph. I read some forums on it but wanted some more opinions. I got under my pickup and where A is located on the picture, there seems to be a lot of movement B seems to be really rusted over. This is not my pickup exactly but just a clear image of what i am seeing. Is there any trial and error things/parts that you guys have done that have helped with this problem?

 

Both A and B could indeed contribute to, or cause a vibration.

Some movement at A is Normal. But it is hard to describe what “some” is.
B is where the U-joint is located. How often have they been greased?
And how many miles are on your truck?

 

Quite honestly it has probably been a while. 184000

 

A lot movement at A is normal, no movement at B is normal. Grease that U-Joint every other oil change.
Make sure all U-joints bearing centers are in the same line.
Now, I had what they call rumble strips on my truck ( kind of a vibration), it was the transmission. I did a complete transmission oil flush and added lubeguard additive, problem solved.

 

Is the vibration in the seat or in the steering wheel?

If it is felt in the seat.
Remove the driveshaft from the truck. Inspect and manipulate each universal joint to see if it is binding or too sloppy.

 

Remember to chock the tires when removing the driveshaft.
The safer practice is to have the truck on jack stand.
The last thing you want to do is run yourself over.

 

This ^^^ and mark it so you can return it where it was in case the wheels turn

 

I had the same problem and chased it all through the drive line and rear springs. It ended up being a torque converter going bad