Thud/knock noise in front end

Hey yall,

Ive got the mystery going on and im not sure whats happening.

When i turn lock to lock driving in 4wd or driving straight and start a hill climb i can hear this noise that sounds under tension from the front end. I can also feel the noise in the gas pedal.
Its not ujoints or a cv because ive replaced both cv's and both ujoints and i still hear it.

I remember hearing it a couple years ago and ive never found it.

Only hear it in 4wd/4low, have heard it y turning in 4wd.

Its not a constant noise and is sort of hard to reproduce time after time. Itll sound when theres tension on the front end.

A buddy of mine suggests spider gears?

Does anyone have any ideas?

Thank you

 

Full lock in 4wd, assuming your on a surface that gives right?

 

Yeah like out in the woods or mud