Recently started noticing that something is not right at our front passenger wheel when the car starts to get over 40mph. Feels like a vibration or something may be loose. Today had the tires rotated and balanced - and that actually made it a little worse. Tires are all good. Put car up on jack and tried to push/pull wheel from bottom to see if there was any movement, but it did not seem to move. It does need new front brakes which will go on in about a week. What would the most likely culprit be to look for that would produce this symptom? Tks.