Hello,

So I think my knee bone is connected to my head bone... Please help me dis-spell this mystery.
I have a 2014 F150 with a 5.0 coyote and what I'm experiencing is a decline in shifting performance as the life of engine oil ages past 3,000 miles. Understandably as the life blood of any living being degrades it can be expected to start showing odd signs of poor health, but in my case this feels far too accelerated.
The engine always starts and runs smooth, the non-graduated pressure gauge has never read below normal and the oil level does not decrease beyond what's expected for that amount of mileage, however the shifting behavior of the transmission starts to feel so clunky its as if there's a bad U-joint in the drive train. The shift points begin to hang, drift and loose any sense of order. One example is when going from park to drive. I have to wait for 3 to 5 second before everything is ready to apply power. If I don't things slam so hard I worry I really might loose a U-Joint. Otherwise during this wait I can actually feel the bumping, jarring and slamming in the power train as if a chest full of boots was tumbling down a hill side. Change the engine oil and viola!, the harsh shifting problem goes away. What's going on here?

My main theory is that the engine oil viscosity is somehow measured by the electronic brains of the truck and that changes to the oil properties becomes one of the many variables the computer uses to "optimize" performance. But shouldn't oil be more stable than that?

If true a follow up thought I've had is maybe this is being exaggerated by using sub-standard motor oil. But even still, apart from my theory above why is engine oil having such a direct correlation with the performance of the transmission?

A few clarification for reference:
I'm in Minnesota so we see big swings in air temperature and humidity throughout the year. I do let it run and warm up in sub 15 Deg F weather.
This truck just turned over 100K last week, although the problem has always been a personality trait since I bought it.
Life these days has me drive through a Valvoline rather than doing it my self anymore and I use their Max-life Synthetic Blend.
This is a 4x4 crew cab.
I have not brought this to a mechanic yet and here's why. This is the second 12th gen F150 I've had. Prior to this truck I had the pleasure of putting the very first 60K onto a brand new 2013 model of the exact same specs. That one was a lease and it had the EXACT same intricacies. Now I own this truck and feel more inclined to fined a solution.

My qualms about the 6 speed electronic transmission don't just begin here. Personally I've never liked it and consider it as chastity to the liveliness this could otherwise have. In prior years I owned a manual shift truck and I've had a really hard time forfeiting control over when and how the gears are changed in my every day driving. Even on a sunny 70 degree day I find that this trans is very irregular and unpredictable. It never does what I want and always defaults to 6th gear overdrive even in town on 30 MPH streets. Have a need to drop gear and make a move?... but it just sits there not getting out of it's own way. I can actually see the computer scratching its own head wondering what to do when the fly by wire pedal is on the floor. I believe that people work best with guidance and machines are to take direct orders, but this thing never does that same thing twice. OK and I'll stop here before this rant carries too far off topic.

Lastly I've considered flushing the trans fluid, but on the flip side heard a few wives tails with cautionary dos and don't of that. Something about sediment, tolerances and harmony. Not really sure enough to go there.

If anyone has any insight I'd be happy to hear.
Thank you for sharing you experiences, knowledge and wisdom!