NP246 transfer case grinding noise

[weaponoffreedom]

Np246...........
intermitent grinding noise.......... IN 2wd
noise will go away instantly when shifted into 4wd or auto from 2wd
no noise in 4wd or 4wd auto
will not shift into 4lo ( the encoder motor is trying to shift but will not and goes back to 4wdhi......loud bangs)

am I correct in thinking that the issue is the t case?

 

[Kira]

Sounds like TC to me.
Whatever those sliders-on-a-shaft (the shaft the motor actuates) are called, or the shaft's bearings themselves, are what comes to mind.
Full compliment of fluid?
What vehicle?