Well, I have this pretty bad shaking starting around 69 mph, and is there strong until I get over 80. But even then, its just diminished, not gone.
First, it seemed to be a tire out of balance, or a bent rim.
Got the tires road force balanced. Still there.
Then I found a set of new rims and tires. Had them balanced and put them on. But still it shakes.
Than I noticed while the rear wheels were off the ground, the drive shaft was bent. Must have happened when the pineon nut let loose. Had the shaft straightened and balanced. Still shakes.
While the dude was putting the shaft back in after balancing, we were talking about the vibration and he took a look at the front CV shafts and noticed the drivers side was very sloppy.
So, I finally had money to get a new shaft and wanted to change the hub bearing while at it, since it was the original still. Got them changed out today. Took it for a drive a little while ago and guess what, the shake is gone. There is still a faint vibration. But if I wasn't so sensitive to vibrations now, I might not have noticed. I will get the other side changed soon and I'm good to go.
So happy I finally found that freakin vibration source.