So I started hearing this clunk/ thud sound from under the truck when moving from a dead stop. It would vary the intensity with it sometimes being a light clunk to a full on thud that I could feel in the steering wheel.

I did all the checks. Looked at the long arms for movement. Checked the driveline for possible U joints going bad. Checked just about everything under the truck that moved. Looked at the engine mounts. Nothing.

So I worked at getting where I could make the noise on demand then took it to the shop I use when I need help. (sucks not having a strong Xterra community up here in the frozen wastelands of MN)

Verdict. Transmission mount.

At least it was not something that is going to have a wheel fly off while driving