>>How can I tell if the input shaft is very slightly bent?  Wouldn't there be

>With the engine out, jack up one wheel and turn that wheel.  The trans shaft 
>will turn,  anrd will wobble if bent.

Obviously! But what if is just very slightly bent?  I did turn the wheel,
and I didn't notice any pronounced wobble.  Such a wobble would make the
car almost undriveable, right?  But a VERY SLIGHT bend might go unnoticed,
and would create stresses that cause mechanisms like a clutch to fail
prematurely.

Replacing a tranny is expensive, and time consuming.  Is it justified? 

Wolf