2003 silverado 2500 HD 115,000 miles. At low speed, low pitch, metal scratching noise coming from under truck. Maybe drive shaft. Noise goes away at higher speeds. Noise occurs at low speed acceleration. However, stops when I let off the gas. I think this condition may be u-joints. Not sure.

 

Kevan,

The best way that I know of is to pull the drive shaft and work the u-joints by hand. If they are not smooth, they will need to be replaced.

 

take a greese gun and make sure they are lubed up.
you should keep pumping til you see it start to peek out of the base

 

Just take driveshaft and wiggle it up and down while turning it slowly. if you have any play the u joint should be replaced. mine made a clicking sound when bad.

 

Sounds like classic U-Joint noise to me.