transfer case problems?

I have a 97 disco with 37k miles on it. Me and a buddy decided to take to off-road for the first time. We ended up getting stuck in some mud. When we were trying to get out, the wheels were spinning and i heard a pop. After that we called someone to pull us out. As we were being out, i noticed that only the rear wheels were getting power. Once i got unstuck, i headed home, but it would not engage in hi or low with out the diff lock being engaged. Any help would be much appreciated.