Ford Repair: 98 Explorer 4x4 rattling and grinding front drive side, ford explorer xlt, explorer 4x4

Question
I am getting a rattling and grinding in the front drvers side of my 98 Ford Explorer XLT 4.0L, automatic, 4x4.It occurs when I apply the the gas. The quicker I excelerate or more gas I give it  the more it seems to grind. Its seems to grind when the torque is greater. That occurs when the 4x4 option is set to auto. When I set the 4x4 option to "Low" it gets worse and when I set it to "Hi",it is even worse than 'Low'. I have had someone to look at it but they could not see anything wrong or out of place behind the wheel. Do you have any suggestions.

Thanks

Answer
Hello and thanks for the question...I'll try to help.
 It sounds like the hubs or 4x4 system in the front end is not fully engaged and is thrashing the whole set up. I would suggest that you strip down the left side and inspect it closer.
Hope this helps,
Erik