I have solved the problem!!!!!!!!! This is almost embarrasing. The tires had taken a set (slightly cupped from being out of balance and or alignment) and were rotated when they were balanced and aligned. This put the cupped tires on the rear and caused a vibration. After a couple of hundred miles they were smoth again and the vibration has dissapeared. Smooth as silk now.
This was pointed out by a tire dealer and his prediction was correct.
Thanks for all your help,
Randy

 

Thanks for letting us know. Sometimes the simlpest of solutions works too.

 

One would have thought that the bonehead balancing your tires would have seen that. Specially knowing that you had a vibration problem !

You just can't get good help anymore !