I have an 02 xlt 4.6l 4x4. w/3.55. I had to replace the rear u joint about A month ago for a loud squeel. Worked great for a little while. Now every time I shift into drive or reverse as soon as the I move either direction It makes a clank. After that I don't hear until I put into park or change drive or reversre. I took the driveshaft off and the ujoints felt fine moved freely. When bolted back up there is no play in the driveshaft. Any suggestions. The sound is definitly in the rearend somewhere.

 

Pull the rear end cover off and check the carrier bearings, they may have caused the ujoint problems to start with.

 

did u make sure to grease the u joint when you replaced it?
if u dont its prone to screw up in a few months

 

My 03 has made this noise a few times when backing up. Thought I ran over something! U-joints seem fine. Never happens when going forward.

 

Efis, you might want to check this out! https://www.f150online.com/forums/sh...d.php?t=297240