Help with a front end grind

[fishnbas2]

I was driving today when all of a sudden when I let off the gas a serious grinding noise came from the front end. When I press the gas it quit and started again when I let off the gas a so on. I suspect this has something to do with the transfer case or hubs. Ive noticed in the past when occasionally backing up I would get a serious clunk front the front end. I dont if this connected but might be. Ive searched this but really havent had any symptoms found like I have. Im in a bind and would greatly appreciate any ideas on what to check or replace. Thanks so much.
I have a 97 Explorer 4.0 SOHC with the automatic 4X4.

 

[jlsparky7]

Sounds like wheel bearings to me.

Rule out dragging brakes first.

 

[fishnbas2]

Well the brakes arnt grabbing. It sounds like a bearing in the transfer case area but not sure. As long as I keep pushing the gaas then it doesnt do it. its like as long as you keep the torque to it then it dont do it but when I let off the gas it grinds. I also have to get up to bout 35 mph for it to start. This is geting aggravating.

 

[99xlsdude]

Had grinding noise in front about 3 years ago. Was front wheel bearing (repair cost about $400 at dealer).

 

[fishnbas2]

Front hubs are good. Looked at front axles and drivers side seemed good and tight in the front diferential housing (but it is the short axle) the passenger side seemed to have a little slack in it (which is the long axle). Joints seem to all be tight on both. Any ideas as where to go from here????

 

[nhill]

how do you know the hub assembly is good? I had a similar grind. It was the wheel bearing in the passenger side hub assembly. Replaced it and everything was all good. I think I paid about 140 or so for it. Not a hard repair. Good Luck

 

[fishnbas2]

UPDATE. Tore down the transfer case and low and behold the fork inside the case was broke. This was what is causing the grinding. But all is well and took about 2 hrs to fix after finding parts. Thanks for the help.