I have a 2003 grand Cherokee limited. Recently my jeep has been making a low humming sound and vibration at high speeds. Its also drifts like if its got a lose or dead spot in the steering wheel at high speeds.

I've already changed a lot of parts due to a similar problem. I changed all four tirod
ends,both front wheel beerings,the ball joints in front, the track bar,right&left CV axels,also
rebuilt the front drive line. I just got new tires and had the balancced twice. I've had the
alignment done twice as well. So as you can see I could really use some more ideas of
what it can be. I'm leaning towards a bad steering stabilizer or calipers flexing or possibly
a bad spring&strut. What do you guys think