Transfer box rebuilt and ready to install question?

Hooorah!!! finally got it rebuilt and ready to install, but before I do I'm gonna drop the ATF & filter out of the main gearbox, then reattach the transfer box. The question I have is is there any issues in doing a dummy run by just installing the xfer box filling it and then after putting the new filter on filling the autobox with ATF, then going through the gears etc. without having either of the propshafts connected???

I just wanna see if everything a) works ok without any load on b) theres no leaks c) theres no grinding or funny noises?

TIA