Clunking front end when braking or release

I have a K5 and one last nerve. I have taken my vehicle to about 10 mechanics now in the last three months with no answers as of yet. The issue: when I apply the brake, something in the front end (which I can feel through the brake pedal) clunks into place. When I take my foot off the brake before the vehicle even moves, this thing seems to clunk out of place. Sometimes this seems to jerk the steering column ever so slightly which terrifies me to think this is all connected somehow. I feel as if something in the front end will brake off onto the ground maybe while I am driving down the freeway, or perhaps I will not be able to stop when needed or even that I may lose my steering. I just had the rear differential replaced as well as pitman and idler arms. I have heard that this issue could be the transmission but just got a thumbs up on that and was advised perhaps it is the transfer case but not sure I understand why that would be affected when I am not even accelerating but then again I am not a mechanic. Funny thing is that this problem is very inconsistent several blocks of braking no problem then all of a sudden it feels like my blazer is all kinds of broken. Also it seems like when the mechanics look it over the problem ceases for a day or two then it comes back and I think this is because parts are removed and then returned and somehow this is affecting things. The best I can figure, this all seemed to begin very mildly last December when I first began to use the 4X4 in the snow sparingly on about 4 occassions; not sure if this is related though. I just made another post about crackling which is brand new issue for me. I am so frustrated and broke, I can not afford another vehicle and I do love my blazer but I don't want to feel like I am gonna die either. Someone please help; I just don't know what to do at this point. :frown: