Hyundai Repair: 2000 Hyundai Sonata, torque converter clutch, hyundai sonata

Question
My 2000 Sonata V-6 with 108K miles develops a noticeable shake @ 45 MPH and continues through acceleration. When I take my foot of the accelerator the vibration and shaking stop immediately. I have not had any decrease in gas mileage, so I have ruled out an ignition problem. My worst fear is that I might have a bad flex plate or torque converter. Any Ideas?

Answer
I doubt the problem is the flex plate.  If it were, I'd expect you to be hearing a knocking or tapping noise when the enigne was running.

The torque converter is a solid candidate.  If you don't have the proper fluid in the transmission (SPIII), have your transmission flushed with SPIII fluid.  Originally, Hyundai used Dexron fluid in their transmissions, but switched because of torque converter clutch vibration issues.