4X4 stiff when making a turn?

When I engage the 4X4 system from 2WD to any of the 4X4 modes (automatic 4WD, 4Hi, or 4Lo), turning becomes difficult and stiff when I make a U-turn or turning either left or right. When I drive and make a turn, it slows down becomes stiff. It didn't do that before when I engage it from 2WD to automatic 4WD or 4Hi, but only to 4Lo. Now it is having this problem when I engage it to all the 4X4 systems. What is the problem? Could be that it needs an alignment? Thank you!