2003 silverado 4x4 vibration

[chapster]

I own a 2003 chevy silverado and in the past month I have a vibration which occurs at 900-1100 rpm. At first I thought it was in the exhaust but now I am begining to think that the vibration might be traveling. Has anyone run into this? Any help would be great.

[gmtech79]

Does it occur sitting still in park or neutral??

[chapster]

No, the vibration is noticed when driving under load starting from a complete stop or with you foot on the brake and keeping your RPM between 900-1200. I have been told to check for the exhaust gaskets. If they colapse that the flanges from both the manifolds and exhaust will rub metal on metal which will cause a vibration.

[planorick]

My 03 2wd does the same thing. At about 40-45, the rpm is at the right point to cause the vibration. Driving me nuts!

[pnewcomb1]

Just a thought...fan/fan clutch?