Here are the symptoms: Car is very difficult to get into gear. Car studders as if it is starting to grab when the clutch (Sachs) is completely in with the tranny in gear. When coming to a stop with the clutch in but with the tranny still in gear, there is a strong vibration that dissipates as the rpm comes down and stops completely when the tranny is put into neutral (maybe the same symptom). Once manipulated into gear, the car drives smooth on both acceleration and deceleration (as long as the cluch is out). I checked out the clutch cable and it looks good and seems well adjusted. The fork looks straight. The clutch does not seem to slip at all. I am confident that the transmission in in excellent shape. I want to blame the throw out bearing but don't knowWhat is the most likely culprit? Thanks.

Drive plate centre bent from not supporting box properly on install.

Maybe bad pilot bearing. Or it fell out.
Any case, it sounds like you gotta drop trans.

You can get this sort of symptom when the driven plate is fitted back to front, the raised part with the springs foul on the flywheel bolts and cause juddering.

Of course it may be something entirely different....

Regards

Pete

Check the bolts holding the bellhousing to the motor. ???