I have a bad 85 Automatic Transmission Vanagon (slips in all forward gears) so I pulled the entire transaxle.   I then removed the AT unit by undoing the four 13mm nuts and separating from the final drive.  Came apart relatively easily with a little persuasion.

I took another Vanagon AT unit that I had "lying around", new paper gasket, new big O-ring and tried to mate them up....it seemed to go on, but was rather tight.   Took a few tries of tightening nuts evenly to squeeze the two units together.   I did this on another Vanagon a few years ago and don't remember it being this tight.

I then realized the Turbine shaft was not seated all the way into the AT (see Bentley 38.3).

My transaxle DID NOT look this:
http://i275.photobucket.com/albums/jj285/baboonia/vanagon/02.jpg
(thanks http://www.weidefamily.net/vanagon/ for the photo)

My turbine shaft was sticking out of the bell housing about 1.5 inches past the center input shroud and could not be seated flush with the shroud no matter how I tried.

So I decided to remove the 4 nuts again and separate the AT from the final drive to see what is going on....well, I can separate them about 3/16 inch (Just seeing the o-ring) but the two will not come apart now....I've tried banging, prying something is preventing them from separating.

Any tips or advice from people who have seen this before?   What could be prevent them from coming apart easily?

Also, I assume next time I should line up/insert the Turbine Shaft into the AT all the way before mating it to the final drive?