Shuddering & rough shifting

[duranduran]

2013 Sho. For the past few weeks i have been experiencing shuddering and hard shifting when accelerating around 30mph and car feels sluggish. Once i go above like 35mps car changes gear and drives smooth. Already changed spark plugs and took car for a test drive, felt good then drove it in the morning going to work and felt the same problem. Not getting any codes either. Any ideas or suggestions?

 

[duranduran]

also have RPMs fluctuating when around 30mph when the shuddering and rough shifts occur.

 

[Texas Marauder]

You don't say how many miles on the clock or if the transmission has ever been serviced. Shuddering is likely caused by the torque converter clutch slipping. I'd drain the transmission and refill with 5 qts. of Mercon LV and a tube of Shudder Fixx.

https://www.amazon.com/Lubegard-19610-Tranny-Instant-Shudder/dp/B0002JMLQU

 

[bthull]

I just had this issue... Rough shifts, shuddering when maintaing speeds around 30mph, and on a couple occasions when accelerating on a highway on ramp it felt like I went over a few sets of rumble strips..
Had the transmission flushed a couple weeks ago and havent experienced any of those issues since.
Just over 138,000 miles

 

[ticoscen]

Ford XL 3 friction modifier fixed my 2011 torque converter clutch shudder.
Tested in 3rd or 4th gear starting at 20mph and hitting the gas.
It'll really shudder before. Now it is gone. Impressed.