Is my truck safe to drive (transfer case question)

So I turned the switch to engage 4wd and at the same time lost traction on my rear tires. As it tried to engage I heard a very loud clunk/snap coming from what has to be the transfer case. Obviously not good. 4wd doesnt work any more but I drove it to work and back and heard no unusual noises, it shifts just fine, and overall runs and sounds like it always has. Im taking it to a mechanic asap but do you guys think it is ok to drive in the meantime?

 

If it drives fine in 2wd drive, you are good to go. Your not going to make anything worse by driving in 2wd.