2003 X5 3.0 vibrating when over 60 mph

[luntany]

Hi there, about half year ago, my 2003 X5 (3.0) had a cracked cv boot in front left, I brought it to a local garage, replaced whole left front axle shaft. About five weeks ago, I had my all four break pad replaced at the same garage, and I was told that my front right cv boot was also cracked, so I had them replaced right front axle shaft this time. My wife has been driving this car in local and no more than 5 miles one trip since then, everything seems fine. But past two weekends, we drove the car on highway, when speed is over 60 mph, we can feel the car is kind of vibrating, not very strong, but you can definitely tell something is not quite right. Here is my question, is it possible that replacing axle shaft causing some unbalance in the wheel that leads the vibration? Will a wheel alignment resolve the problem? Any other possibility that can cause vibration? Thanks in advance.