2002 Chevy Silverado noise in drivetrain

First thing you can do is to check the universals they could be causing that.

Secondly if your vehicle has a slip yoke on the driveshaft, it may have to be removed and re-greased, its a common problem with vehicles with slip joints. If I recall right though your vehicle is known for clunking and you may want to call up the dealership and ask if thers a TSB out for it.

If those are all good check your tranny mounts and the fluid level.