Contour Enthusiasts Group Archives Forums Modifications Suspension vibration rear control arm related??

First let me say...yes, I did a search. In fact, I came across this thread that seems to answer my question:

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=susp&Number=475093&Forum=susp&Words=vibration&Match=Entire%20Phrase&Searchpage=1&Limit=25&Old=allposts&Main=475093&Search=true#Post475093

I'd still like to pass this by the Masters of Suspension, though.

I also have a vibration at 60-80 MPH. Actually, I have it at lower speeds but it's almost negligible. It seems to come from the rear because the steering wheel doesn't vibrate more than any other part of the interior. It seems to be tied to the RPM of the tires, which has always confused me. If it's a suspension component, how could my speed of travel affect it? Anyway....

I've had this through 2 sets of tires on old wheels and new tires on new(er) wheels. I figured something had to be damaged, but didn't know what to look for. I have rotated the wheels in the past and it didn't seem that the vibration moved when I did so.

Now I just came across the thread above so I haven't been under the car to look for obvious signs of bending. It seems the parts aren't very expensive and it's most likely a DIY job (right up my alley!!).

Basically what I'd like is confirmation from the Masters of Suspension that I may be on the right track. Also, any other ideas that could be causing this would be helpful and appreciated.

Drive axles. Mine did the same thing, almost two years I suffered with it paying for rebalancing, etc. It just kept getting worse. It got to the point that under cruise it was ok but any slight acceleration would result in a shimmy throughout the car even though the steering wheel didn't wobble.
The dang passenger seat would shake when I'd accelerate. Any speeds above about 40-45 mph would vibrate and progressively get worse as I went faster.
In the early days it was just at speeds of around 70+ but as time went on the speed that it would start to vibrate would get worse. OF course, always under cruise the vibration lessened.
Hope this helps.