Please help with noise identification

[doneinne]

I have a 1999 Eddie Baur Explorer with AWD. It sounds like the noise is coming from the rear of the vehicle. It occurs when the vehicle is hot after driving for 45+ miles. The noise occurs the first few feet when taking off or backing up from a stopped position. It is louder when backing then it is when going forward. The noise is hard to explain. It's like a studdering, skipping or grinding sound. Like something is frozen up and doesn't want to rotate. It doesn't do it when driving around town for short distances. Yesterday I was parked on an incline with the front end facing down hill. I had to back up hill out of the parking stall. When I did this the noise was loud.

I replaced the U joints and the rear differential fluid.

I believe my rack and pinion is bad. I leak power steering fluid from behind the front passengers side wheel. Is this noise related to that? Bearings? Transmission? Please help.

 

[DjDom]

Does it only happen when you're shifting from Park into Drive or Reverse?

It's probably the slip yoke.
If so, try this:
http://www.explorerforum.com/forums/showthread.php?t=106307

 

[doneinne]

No, it doesn't make any noise when I shift. It makes the noise when I start moving. About the first 3 or 4 tire rotations, then it stops.

 

[1992fordgreen]

Rear brakes scraping, fuel pump, emission lines hooking up into the wheel...

 

[doneinne]

Bump