Clanking like sound in the front end that sounds like either the drive shaft or the gears in the transfer case? Hard to hear unless pulling in the garage where the sound bonces off the walls. The clank happens, I am guessing about 8-12 times per wheel rotation. definitely sounds like a rotating related clank (i.e not the brakes, etc.)

Sorry but I just found out that you have a 2002 GMC Sierra --- Anyway is full time or part time 4 wheel drive? Do you notice what side the noise is coming from? Or is from underneath the vehicle? My suggestion would be to jack up one wheel (front) at a time and rotate the wheel. Do you hear any noise or is there excessive drag when the wheel is rotated? If you you do this to both wheels and find out that they are rotating well then we will take it to the next step. Most of these newer vehicles have the wheel bearings together with the hub assembl;y. that is usually what goes bad. They are not cheap--- roughly 150.00 I have not changed one in a couple of years----but for the average joe it can be difficult. So try jacking up the wheel and rotating it first before you do anything else. This as should take alot of the guesswork out of it. Ed Sorry but I just found out that you have a 2002 GMC Sierra --- Anyway is full time or part time 4 wheel drive? Do you notice what side the noise is coming from? Or is from underneath the vehicle? My suggestion would be to jack up one wheel (front) at a time and rotate the wheel. Do you hear any noise or is there excessive drag when the wheel is rotated? If you you do this to both wheels and find out that they are rotating well then we will take it to the next step. Most of these newer vehicles have the wheel bearings together with the hub assembl;y. that is usually what goes bad. They are not cheap--- roughly 150.00 I have not changed one in a couple of years----but for the average joe it can be difficult. So try jacking up the wheel and rotating it first before you do anything else. This as should take alot of the guesswork out of it. Ed