Loud noises coming from front end 97 4x4 explorer

[CRXsk8er]

Hi I just bought a 97 Explorer Sport. It has about 131,000 miles on it and when I put it in 4x4 high the light comes on but i dont hear anything engauge. when i turn to 4x4 low it engauges and is fine. but whne its on any setting it makes loud sort of grinding noises just whenever I turn, the vehicle is hard to turn when the noises happen and will sometimes pop and then drive okay till I make the next turn. Any suggestions? Is it a hub problem? I haven't really driven this vehicle in 4x4 before so I don't even know how it is supposed to act but im sure its not suppose to mess with the steering as much as it is and make noises like this.....when its set on auto it should be 2 wheel drive unless it senses it needs 4 wheel....well say i back out of a parking spot or pull out or make a turn from a complete stop the wheels bind up and make the steering wheel really stiff and then it will pop and be ok til the next turn....im not fimiliar with 4x4 but its like its stuck in 4x4 high....anyone?
i know about driving 4 wheel on dry payment but it does the same in sand and wet roads
anything i can clean?


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