RetroGamer

favorable

Kindly specify the year, make, and model, since the responses may vary significantly based on whether it is a V8 or V12 engine.

Do not remove the transmission prematurely, since the flex plate may be intact. I was examining many options about the vibration based on your article. Prioritize the examination of the simpler elements first.

If the vehicle is in neutral at 70 mph and coasts without vibration, presuming the engine returns to idle, I would consider it to be connected to engine speed. The coast test would likely exclude differential, driveshaft, wheels, some gearbox components, and other drivetrain elements. I would closely examine engine vibration at certain RPMs and higher. Initially, it is essential to inspect the engine mounts and gearbox mounts. There may be an unbalanced component rotating inside the engine. Inspect the engine fan, since I anticipate it is the antiquated steel variant. Ensure all blades are intact. Verify the harmonic balancer. I see that you have substituted the converter. Have you substituted the flex plate?