2009 shudder between 30 and 40

My 09 has started shuddering when speed is between 30 and 40. It seems transmission related as it doesn’t happen when coasting, it feels like a manual transmission trying to start in a gear too high. And it only happens when accelerating, does not occur when slowing down. Could it be low transmission fluid? What do I do to diagnosis this?

 

How many miles? My ‘06 did this at about 150k. My local transmission shop did a fluid change and it went away.

 

Check out a addictive called Dr tranny on rock auto. I flushed my transmission this weekend and added it to fix my tq converter shutter.

 

205,000 miles. I replaced the trans fluid about 5 years ago, around 170k

 

Does it do it in 4th gear?
When it does it, drop the shifter in to 4th and see if it goes away.

Or, keep accelerating foot ON gas pedal and “just barely” touch the brake.
Not enough to apply the brakes, but just enough to get the brake lights to come on. If it goes away, it’s probably the torque converter.