I was gonna say, why do you have it in 4wd while in a parking lot? Is it completely snow covered? If it is dry or merely wet pavement you should NOT have it in 4wd. tommudd is correct (as usual) the really hard steering is likely binding, which means you could be damaging your KK's drive system. 4wd is for loose surfaces ONLY (ice, snow covered, gravel, sand, dirt, mud) not for driving around in your local mall parking lot.
Now, if it is doing this while on the aforementioned loose surfaces, then you could have a problem with the drivetrain. Take it to the dealer (if under warranty) or your local mechanic and have it checked out.