I've have got a 2014 F150 Crewcab w/5.5' bed, singe piece driveshaft. I purchased the truck from the local Ford dealer with roughly 50k miles and it now has 60k miles. It was buttery smooth for the first 8k miles until I started hearing the driveline clunk in the rear of the truck at stops.
After researching on this forum, I purchased the Ford Kit, 9L3Z4W602A, with the grease and band clamp. Greased up the yoke and within a couple days was noticing the clunk again, it may have never been gone, but I don't recall for sure.
I had my truck in to the dealer for some other work, rear main seal and pan gasket leak and had them look at the rear end or whatever was causing the noise. They could not duplicate.
After searching some more online, I found that someone used a file to remove some burs from the opening of the yoke. I purchased another repair kit and smoothed out the opening of the yoke splines before thoroughly cleaning and applying a second round of grease.
That was three days ago and after a couple hundred miles, I can faintly hear it coming back.

I would rather not have to rely on my dealer to repair this. Does anyone have a part number for a replacement slip yoke?
I have no problem replacing the slip yoke on my own, if that will fix it. No need to replace the entire driveshaft.
I do have an extended warranty, but it's such a hassle to get it into the dealer, have them duplicate the problem, and lastly to admit there is a problem.
Any help is appreciated.
Al

 

Sorry I can't help with the part number, but about 3 years ago my '05 was getting the clunk/thump and grease was only fixing it temporarily. I called a local driveline shop that has made some shafts for me over the years (so I trust his expertise) and he told me once the nickel plating gets worn out of the yoke, lubrication will basically be a temporary band-aid. Replacing the yoke was the correct solution. I did as he recommended and it's been quiet ever since.