i have a 2004 chevy 2500 4x4. just wanna share some information i've learned to help some others out maybe. these trucks and im assuming most gm made 4x4 late models do not have a way to regrease the front hubs. which means after about 100,000 miles you'll start to hear some grinding in the front. thats because the guys at the lube shop cant grease em. they have no nipple for a grease gun. i call a machine shop and they tell me that u cant hone and repack them either. so for maintenance purposes you have to replace your front hubs every 100,000 miles. that doesnt sound that bad until you discover that front hubs cost about $250 per side, so $500 total. then you have to pay somebody to put them on or do it yourself, which i'll go ahead and let you know is not easy for the simple fact that everything on the frontend is put on with threadlock. i've done it and its not rocket science, but its frustrating because of the price and the threadlock. hopefully this will help somebody out, because the noise was a little hard to diagnose for me. its alot like brakes, i mean even after a certain point u will get some shimmy in the pedal, so u might think its the rotors or the brakes. so just remember that noise in the front could be your hubs. especially if you're over 100,000 miles. also fyi, the new hubs DO NOT have any way of being greased either. so they too will have to be replaced later on down the line.