Hello Listees:
A few months ago I bought an in-expensive '90 Vanagon, which had
some known engine issues, and very little known about its prior
mechanical history, other than it had not been driven or registered
for several years.  The previous owner said that it was being
started and moved in and out of his shop every day for maybe 2
months, for parking purposes.  I simply got it started long enough
to drive it up onto my trailer, got it home, reversed it back off
of the trailer, and around the yard.  It seemed to shift and work
properly in drive and reverse.  I let the van sit for about 2
months.  Last week I started working on the van, to get it running
well enough to pass the state safety inspection this month
(beginning next month all vehicles have to pass a $$ smog sniffer
test, and I don't want to deal with that if I can help it).
Anyway, I was surprised when the van would not shift into reverse.
After many tries, I eventually got it to engage, but not reliably.
The 3 forward drive gears seem to engage fine.  I checked the ATF
level on the dipstick, and found the level to be very high, about
5.5 inches above the "cold" level.   I checked the differential
fluid level, by sticking my pinky finger into the fill hole, but
could not detect any fluid at all (could be 1.5 inches or more low
on fluid).  Bentley says that the seal between the transmission and
the differential is likely eaking.  I drained the ATF fluid, and it
looks "normal" red.

QUESTIONS--
Are there any other possibilities for the high ATF fluid level, and
low diff. fluid levels, besides the leaking seal?

If the seal is leaking, would the differential fluid have leaked
into the transmssion with the van parked for the last few months,
or does fluid transfer mainly take place only when the trans. /
differential is operating?

Assuming the seal is the culprit, and not knowing how far the van
may have been driven in this condition,  what are the chances that
the transmission may have already suffered permanent damage?

I really don't have the time to investigate & replace the seal
before the end of this month, and I really want to drive the van
about 20 miles to get that safety inspection sticker.  If I refill
the ATF fluid and diff. fluid levels to their proper levels, and
the reverse gear begins work again, what are the chances of my
damaging the transmission by driving it 20-30 miles with the
leaking seal?

Any advice or suggestions from listees who have experience with
Vanagon auto transmissions & leaking seals is greatly appreciated.
Thanks in advance!

Cary