strange popping/ clinging noise when in 4wd

1999 Tacoma v6 with locking hubs. My 4wd works but when I start to climb a steep hill or go through some boggy mud I hear this loud echoing clinking noise (best I can describe it) it sounds like its coming from the passenger side front but I might be wrong. Its hard to tell when I'm in the truck. I was thinking ujoints at first but that would be on the drivers side. Its like gears are slipping cause when it starts doing it the 4wd works but I can tell its not pulling up the hill the way it should. I just hope its not something in my diff. Anyone have this happen?

 

Is this a refference to manual locking hubs?

Is so, try various combinations of the hubs locked and unlocked to see what changes. Put it 4WD and only lock one hub. If the sound goes away you've isolated it to that corner.

You can even try 4WD with neither hub locked.Still got the same noise? Looks like its the diff.

The diff, the CV joints (inner and outer) and the hubs and bearings could all potentially make the kind of noise you are describing.

 

Thanks for the reply. I'll try that.