Dfather99
Newbie
If all else fails, drop the torque converter pan, disconnect the torque converter bolts, and push it rearward away from the flexplate. Run the engine.
If it still vibrates, it's the engine or accessories. If it doesn't, it's the trans--which probably means a failed torque converter.
ALL of this assumes this is RPM related, not speed related. Does it vibrate at the same RPM in first gear? Third? Neurtral?
What is your scan tool showing for misfire history?
It's an obd and no check enginelight is on I'll check to see if any codes come up.