2002 Sierra Denali AWD Issues

[demonte1997]

Only when on the gas pedal. The truck makes a rhythmic clunking sound that you can feel through the floorboard and in the pedal. Also can feel it in the steering wheel but not as much. Sound gets less noticeable at higher rpms and speeds. Starts at 10mph and continues up to 65 where it starts to mellow out.

 

Was wondering if anyone here could steer me in the right direction. Had a lot people try to offer hints at what it could be and I've heard everything from front/rear diff to transfer case. Already replaced u-joints and wheel bearings.

 

Or does anyone in CT know of a good dealer to look at it?

 

Thanks in advance.