I recently have been doing some transaxle removal and installation on my 86
vanagon with AT.  I found a pretty good improvised method to handle the
trans on a floor jack.  I have a cheap 3 ton floor jack with the little
swivelling steel cradle on top.  I took that cradle off.  Then I took some
1x12 shelving board and bolted it through the hole left by the cradle using
big washers to prevent it from damaging the wood.  It is long enough to fit
the length of the trans with a little extra length.  I found the best place
for the hole to be centered on the 12 width of the board and 8.75 inches
from one end of it.  That end will be where the bell housing will sit.  It
is the heavy end of the transaxle assembly.  Then I used 2 of those
racheting hold down straps to secure the trans to the board.  Otherwise it
will slide around and fall off, or get off balance and topple over the
jack.  I left the bolt holding the board to the jack slightly loose so that
I could make adjustments in angle as I put the trans back in.  It also
allowed me to rotate the board on the jack so that I could roll the whole
thing under the van.  Hope this will help somebody!
Edward