1997 Chrysler LHS Strange vibration

Drive Train Axles Bearings problem
1997 Chrysler LHS Front Wheel Drive Automatic 135000 miles
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I have a chrysler lhs 1997 with 135.000 miles
Car is done well all these years.
The problem I have now is that the car will drive well untill I get to about 60 ph and it gets a sort of vibration, after a while at the speed the vibration will fade away but if I reduce speed and then try to go back to where I was it will make the vibration again untill I get to speed of 60/65/70/mph

I have no idea of what this could be
Maybe from the drive train?
wheels?

Please give your opion.

Thanks
Emil