when i put my blazer in 4wd and go straight it's fine, but, when i go to turn( not all the way) it will just stop and wont move. it's almost like it is in neutral, it will rev up and wont move. but as soon as i put back in 2hi it's fine. whats wrong with it. i was also on concrete when i tried it through. thanks

 

Binding in 4wd is normal when turning on high traction surfaces. The tires are effectively locked together, but trying to spin at different rates due to the different arc diameters while turning. 4wd should not be used on high traction surfaces.