Horrible Noise when turning

[jbrown123]

I have a 1998 Explorer 4.0 XLT and I have been hearing this noise for awhile now. Every time I turn at a higher speed I hear this noise it's hard to describe the noise it's like a clunking or tapping noise when I turn. It almost sounds like metal is slapping up against something. It only makes the noise when I turn at a higher speed. When I turn really slow you cant hear it. It sounds like it's coming from the rear of the vehicle and when you sit in the back seat you can feel it on the floor. I have checked everything but I still cant find the problem. I changed the rear differential fluid and added the friction modifier, and I changed the transfer case flud and added some friction modifier to that too, but still the noise is there. I checked the U-Joints and they all seem tight. I don't know what else to check, so if anyone out there can guide me in the right direction I would greatly appreciate it.

 

[BrooklynBay]

Did you look for scrape marks in the wheel base? How is your alignment? Are any exhaust parts loose?

 

[jbrown123]

I have looked at everything. New wheels and tires, new exhaust, and just had an alingment 2 months ago when I put the new wheels and tires on. I looked for anything that could be rubbing, but I did not see anything. It's weird I only hear it when I turn at higher speeds. I asked around at these auto repair shops and I have been told the transfer case and than another one said rear differential, so I don't know where to even start.