I'm Chris, Thanks for allowing me to help you here on Just Answer.
when i took it to the transmission shop they test drove it and said that it was the torque converter.
The vehicle has 153 k miles
the sudder seems to be like both what you said but it is not very long when it does it for about 2 seconds.. the motor doesnt rev up while doing this.
Never tried shifting every 10 seconds but i have noticed today that it will not do it when it is not in overdrive cause of the rpms and i tried to make it do it today with negative results. Seems to be only in overdrive
Does it feel more like #1 or #2
Running well =W
Running with this concern =C
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#2 wwwwwwwwwwwwwwwwwwwww cccccc wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww cccc wwwwwwwwwwwwwwwwwwwwww
OK at this time I fel like your not feeling a torque converter shudder. I believe its a slight engine miss under certain loads being a coil and or plug not at 100%.
The easiest way to get a misfire is to go about 45mph up a slight grade and gradually apply alittle more throttle and you feel intermitent jerks.
The easiest way to get a converter shudder is to do 55mph and cruise on flat ground. Start pressing down o nthe throttle little by little. You should notice the rpms pop up about 500 when the converter clutch disengages. If it pops up more than this then the converter disengaged and it shifted to 3rd. The converter also applies in 3rd. When a converter applies you will notice the rpms steady out then drop about 300 and it feels kind of like when you press the gas your not accelerating as much as it feels like when going under 45 mph.
Now that you know how to determine which it is and how they operate you can better determine which is the fault here. A newconverter should have fixed a converter shudder and at the least made it better or different. A dealer IDS scan tool will pick up a misfire in about 1 mile of driving as would it be able to monitor a converter and see if its shuddering on engage or disengage.