My F150 has started shaking when in 5th gear. Sometimes will feel like a rough road but has occasionally given a hard jerk. Usually occurs when in 5th and traveling around 40-50 mph. Accelerating makes it smooth out. Any suggestions would be appreciated.

 

Check my signature below. Additionally, which tranny type (i.e 4R70W).

 

2014 F150 3.5 ecoboost 4WD 6 speed automatic.

 

So it's a 6R80 tranny.
My alldata software covers up to 2007 any car, sorry can't provide you the pinpoint tests on your 2014. Someone else should be able to jump in and give you some kind of help. It might be more helpful if you can let us know what's the mileage and when you changed your fluid and are you the first owner and any CEL or ford's specific DTCs from your scanner, something like that.
You can also check if there is any known TSB on your 6R80.

 

I am not too sure your vehicle has a trans problem.

Can you have your vehicle checked for codes ?

We could be looking at an engine misfire/ performance problem..