[4x4cherokee96]

okay heres my issue, i bought a 1996 grand cherokee yesterday and i was told it never ran for 1 1/2 years, because the ignition coil went, and the owner thought it would be smart to keep trying to start it.. duh and the starter burnt out.. lol so i bought the jeep and got a used starter and used ignition coil. and installed it. sure enough... i had to boost it.. and she started right up. but it ran really rough, and started blowing black smoke out the tail pipe really bad! then that went away. when i looked over it more i found that the drive shaft that connects the front axle and transfer case isnt their... and the lever that switches from 4x4 to 2 wheel drive wont move.. and theirs a clunking noise in the front when driven..i found somehting that looks like a "c" thats in between the axel and the center of the wheel.. on both sides are loose an i believe thats whats causing the clunk.. but what is that? universal joint? and why wont it switch from 2 wheel drive to 4 wheel drive. its stuck in 4 wheel drive right now. but obviously its not because theirs no stupid drive shaft.. what im asking is what that "C" looking thing is.. i need this thing fixed asap so i can drive it!