I have a 2006 GMC Sierra - there is a very loud clanking/snapping sound coming from the front drivers side wheel. It only happens at low speeds, once I get above 20-25 mph it stops. It happens about once or twice every three or four days. It is a 4wd w/ 55k miles. No off road just back and forth to work. It seems like it happens most after I take a turn and straighten out my wheels at low speeds but it has happened while turning at low speeds too. Any suggestions? Thank you in advance.