Transfer Case Issues?

[Berg]

I've got a 98 XJ that I'm actually trying to sell. When you engage the 4 wheel drive and turn the wheel, it has horrible wheel hop or skip. It doesn't seem to make a difference if your on dry pavement, snow, mud etc.... It is also rough shifting out of 4 high to 2 wheel drive. I at first suspected the transfer case, but it doesn't make any odd noises when it's skipping and hopping in circles. Which makes me think that it's not the transfer case. Any help would be appreciated.