If it is just a leaky pan that pan is very picky about how it is
sealed and requires very little torque on the screws as they are
tightened.  The seal is still available to buy but the fit is awkward
and needs "prewetting" with ATF.

There may be some cruft or goo or crap on either surface from the last
guy who serviced it.  both surfaces should be very clean.  Don't
scratch them trying to remove whatever.

Some people put some sealer goop on to reseal it.  I don't recommend
this, be only very finicky about cleaning and following the torque
recommendation in the Bentley manual.  Don't tighten one screw before
the others, get them all finger tight and approach the torque
together. Mind that the rubber seal is positioned properly, as well.
NO LEAKS.

C
--
If you're in my band you can't have too much of a sense of dignity. --
"Weird Al" Yankovic