2015 stock 4x4 double cab driveline shudder

2015 stock 4x4 double cab 5 spd auto, 50,000 miles:

I've read dozens of threads and can't seem to find one that absolutely fits.

From 20-30 mph and sometimes 35-40mph, the driveline shudders noticeably only when in the D gear and only when I accelerate "gently." [The shudder is akin to having a manual in too high a gear at a low speed]. If I accelerate hard in D or if I accelerate in the 4 gear, there is no shudder. Also, there is no shudder if I rev the engine slow or fast while in neutral or park. Also, new tires and brakes (to eliminate any discussion those are the culprits).

Inspection of the u-joints and carrier bearing part do not reveal any obvious issues.

What's the cause and solution, if any? Seems to be getting worse. Thanks

 

Someone here is going to know better than I will, but if it’s stock, I’d start with greasing the slip yoke.

http://www.lowrangeoffroad.com/ptfe...-ford-motorcraft-xg-8-ml1167-31508-42027.html

I’d wait for a few of the experts to chime in before you order & take my word for it, but that’s where I’d start.

 

Update: Under warranty at no cost to me, the dealership had to install a new torque converter to eliminate the shudder. 10,000 miles with new converter and no shudder.