2000 Ford Taurus You Drop Transmission Replace Torque Converter On Taurus

Do you have to drop the transmission to replace a torque converter on a 2000 Ford Taurus? My transaxal light comes on and blinks for a certain number of miles. Shut the engine off for about 15 minutes or so, and the light is off. Then a certain number of miles again it comes back on. It will not shift out of OD. My transmission is, 1 D OD. There is no fluid leaking, no smell. I shift from P R N OD, I can hear the gear shifting. When I shift to OD, and D, I don't feel the shift. Sometimes it hesitates going to OD. The gear shift diagram is: P R N OD D 1.

Thanks