2001 4x4 150, rt front feels like someone is kicking the floorboard. Happened once about 3 weeks ago and again today. Only notice it at under 35mph. worse when going straight. Is there any way to tell which is the problem without tearing into it. I can get rebuilt shaft with cv joints for under $80 but hub bearing is over $230. dont want that expense if I dont need it. Any thoughts?