93 astro; awd problem

what is the name of the gear box that the front half shafts go into. im trying to fing the part and no one understands me. also i have been having this banging and cracking thumping sound coming from the front of the vehicle. sounded like a bad cv joint. but the left and right cv joints seem to be good. but the gear box(which i want to call it a transfer case)is leaking and sounding rough but not making all that rough banging sound. anyone have an idea or suggestion.

I believe you are searching for the term: Front differential

But your transfer case and it being low on fluid or needing it changed could cause the issues you describe as well.

just to report. the vehicle was fixed. it was the front differental.180 dollar part.easy out and easy in.