Hello,

Some history first.  I owned my '84 since new.  About 20 years ago, the
oil drain plug threads in the case stripped.  I inserted a Heli-Coil.
From that point on, I cut a new cardboard drain plug gasket to use for
each oil change.  One reason that I switched to cardboard was so I
didn't have to tighten the plug very tight.  I never had a leak, until
now.

Starting with the last oil change there was a small leak.  As time went
on it got worse, but I thought that it would fix with the next
cardboard gasket.  It didn't.

Because the shoulder on the OEM drain plug is small, I changed to an
aftermarket drain plug with a wider shoulder.  It came with a nylon
gasket which I then used.  It still leaked.

Today, I tried a cardboard gasket with the new plug.  It still leaked.

So, I took some photos.  They can be found at:

   http://5by9.net/busleak

In photo a13.png, starting from the center, the Heli-Coil can be seen.
Around that there appears to be an insert in the case, perhaps steel.
Then, the case material can be see around the insert, as well as flaking
plating of some sort.

What concerns me is the artifact at about 11:00 o'clock.  Both the
insert and the case seem to be breached at this point.  Also, please
notice the bubble in the plating above and to the left of the breach.

Photo a14.png is from a different angle and perhaps shows the artifact
a little better.

Could oil be leaking through this breach, under the plating, and then
out?  If not, what else could the leak be?  It's getting worse and will
have to be dealt with.

Most importantly, what is the fix?

Thanks,
Mike