Need help bad!!!

i have a 2004 gmc sierra 181,00 miles z71...when i am going around 35 mphs there is a noise in my front end or under my truck somewhere that sounds like metal grinding or something is loose and its contiunually getting worse please help anything would be nice:crying:

Welcome to AF, reallistically no one can get a handle on this from their desk. Check for loose shocks or any worn loose steering/suspension components or wheels and wheel bearings, all basic stuff for what you are experiencing.

I have a similar problem in my 01 z71 but it was only in first gear. when the tranny would shift to second the sound went away. At first I thought it was the u joints so i changed all of them (front and rear shaft). But that didnt help much. Also I changed all the fluids, transfer case, front and rear diff, tranny I had just done recently about 3 months ago. I thought that would fix the problem too but nothing. However what I did learn is not to put tranny fluid in the transfer case. Its a special blue fluid that I had to buy from the dealership ($9/qt) which looks really cool. I wanna say is GM Auto trak but I can't recall for sure.

drive down the road and swerve from left to right, if the pitch of the grinding noise changes, then you have a wheel bearing failing. to figure which bearing it is, drive on a road that has a long curvein it. if you turn to the right on the curve on the noise diminishes then it is your left wheel and the oppisite for the other way.