knocking sound(maybe from t-case)..

[hokie98zj]

so just a few minutes ago i dropped my sister off at work.as i pulled up to let her out, a knocking sound started(sounded like from the t-case).as i go a little faster,it starts knocking faster.(i guess kinda like tying a zip tie to drive shaft,as you go faster the zip tie hits faster and faster).moved to a parking spot and i see drops t-case fluid leaking in a couple places.would low fluid cause the knocking sound? just add more fluid?

i have been using 4-lo a lot going up and down my hill and a couple times to get people out.maybe that forced fluid out being used so often? my zjs parked for right now until i get this figured out.

there were a couple times i was in drive while in 4-lo(most of the time i was in 1st or 2nd).max speed was about 10mph. could that have caused fluid to leak out? clear pavement driving was minimal(the few patches from people shoveling snow out of the way.as soon as i hit clear pavement i unlocked the hubs and switched back to 2wd).

i was in 2wd when it all started.didnt try 4wd after i heard the sound.theres some vibration to go with it btw.