Nice to know this fixed the problem for you! I'll take the drive shaft out this week and hopefully my problem will have the same solution yours did. I'm excited to finally rid myself of this noise.. thanks again sunogbahay.

 

Well not to kick up an old thread, but I have had a similar issue myself on my 2001 F350 Dually.

Not really a grinding noise more of a rubbing/vibration. If I turn the wheel to the left while under power (going down the road at 40+mph) its much more pronounced.

Going over dips it seems to do it when the load is on, and when its fully off.

I have replaced

Both front wheel bearings and needle bearings, both sides upper and lower ball joints, all the u joints, and the hanger bearing. All 4 shocks are new.

It really feels like its coming from the passenger rear, when I hit a bump on the drivers side everything feels solid, but when it comes to the passenger rear going over a bump it does not feel the same.

Yes I have jacked it up and checked for play and it seems fine. I have even jacked it up and supported the rear end and put it in gear. There doesnt seem to be any noise or vibration when I did that.

I dont know but I think I will just replace the inner and outer rear wheel bearings this weekend and see what that does. :S

 

Try greasing the the spline on the drive shaft and see if that takes care of your problem.

 

What about pulling the rear drive-shaft completely and driving the truck in four-wheel drive. At least then you might be able to exclude the drive-shaft as a possible source of the problem. I'm not sure what speed is okay for driving with only the front wheels engaged, but I would think that 40 mph, for a limited time, would be fine.

 

You should be fine doing that. Sence your going to have it off anyways check all your u-joints. Im not positive that the drive shaft is your problem, its just one more thing to rule out that wont cost you any money and only 20 mins. of time. I would pull the drive shaft inspect everything grease it up and see if it still makes noise