diff issues - vlsd

hey guys i found some clunking in my car, and when i was feeling shit underneath it kind of sounded as if it was my diff, anyway, i took it out and swapped in my open diff, the sound is not as loud but still there, hence im wondering if clunking was because it was low on fluid ? and if there is supposed to be some rotational play from the driveshaft/axel sides, let me know if you guys know anything about this, thanks. -im not even sure if its the diff and im planning to swap it back in with an abs driveshaft, cause before i used a non abs driveshaft

also when i took it out if i jerk the input shaft back n forth i hear loud clunking, and around the fill bolt everythings all wet, could it be the liquid leaked out ?