Vibration caused by rear springs?

[ponkotsu]

Got an annoying vibration at 55-65mph. Everything in front end seems fine. I've rotated the tires and it doesn't change. Got new brakes and rotors. Thought maybe it was CV joints, but they seem nice and solid and no noise. I actually think they aren't original because there is still labels on them.

Reading the Ford service manual, they say that drive shaft angle can cause this vibration. Since my rear springs are sagging about 2-3 inches, I wonder if this is the cause of my vibration.

Anyone ever experienced this?

 

[JCat]

I had 2 bent wheels that caused this. According to 3 tire shops, the wheels were within tolerance. The 4th one that I visited said to replace them. I did and the problem disappeared. New tires helped too . . . Once they wear funny, you are screwed.

Before that, I replaced everything, including front axles, ball joints, bushings, shocks, drive shafts, tires, . . . etc. Everything !