What is wrong with my FOUR WHEEL DRIVE!!!?

I have a 97 f250 7.3 turbo diesel automatic , auto locking hubs with a floorboard 4x4 shifter. I decided to hook up to a 6.4 08 twin turbo diesel lol. It was on pavement and he beat me in 2wd but i put it in 4x4 and i beat him, than i stopped and once i stopped he pulled me without me knowing like an idoit and i had a loud boom noise come from my front axel and now my 4x4 clicks evertime i put it in and wont stop clicking What could be wrong with it?