I trashed my A833 leaving the driveshaft in. Basically welded a gear to the output shaft because of a lack of oil. After rebuilding the transmission, it became obvious why.
And in worse cases it will weld the output shaft to the input shaft at the point where they come together and you find out your engine has been spinning for 300 miles while you were towing it. :banghead:
Seen that one before, and it looks like this when it happens.
Notice the tip of the output shaft is still in the input shaft where the needle bearings used to be?