I have this annoying thumb thumb noise when i drive. it comes and goes and is starting to get annoying. It started after i stopped real fast. I thought maybe flat spots on my tires, well thats not it, i changed my tires. i have no clue what it is. I was thinkin maybe the ball joint? (where the wheels sits on, not sure what its called) is loose?....i dont know if anyone can help.......