vibration at >60 mph in '04 deville

my deville has a small vibration betweed 65-70 mph but not outside that range. Runs smooth at 75 and over. Front tires are in good balance and the problem has not gotten bettter or worse after 20,000 miles of driving. Steering wheel has no play. Tire rotation does not make the problem better. Any thoughts?

Tough diagnosis, I would look at any factory TSB's concerning this issue, GM did have some problems with front hub/bearings causing this in Buicks and Pontiacs. Did it do it with the oe tires?

bought the car used with 4 brand new continental tires mounted on it. This was 2 years ago. I cannot remember if the problem existed from the very start but it has been in there for a very long time. vibration is slight. this car has chrome factory 17" wheels. Braking is perfectly smooth and front end shows no alignment problems, tire wear is totally normal for the 20,000 miles, no cupping or uneven treadwear. After jacking up front end and pulling as hard as I can on the tire/wheel assembly I do not notice any lateral movement in the hub assemblies assuming I could pull hard enough to find a problem. For sure there is no detectable movement by hand touch

The bearing issue was not play but the mounting hub was slighly off center.

thanks maxwedge!! I will check on this possibility!!

what i would do is have my tires road forced thats like balancing but they check the road force of each tire and if u have a bad tire it would show and should break the tire down from the wheel and turn it to the best position that it would roll better and they should put the better tires in the the front. it might be expensive though and not all shops have a balance machine that road forces tires