If the pavement is anything other than snowy, muddy, or even icy, you should not use 4WD as it causes that exact symptom as the drivetrain tries to move at a different rate in the front than the rear when making tight turns.
If you want to check your wheel joints (The ones in the front axle), put the Jeep in 2WD, turn the wheel as far as it will go, jack up the side that is pointed inward, and look at the u-joint. Because the axle has no load, you should be able to check for deflection easy enough.