On Wednesday, June 3, 2015 at 10:11:49 PM UTC-7, Don Foreman wrote:
On Wed, 03 Jun 2015 19:52:26 -0700, Larry Jaques
wrote:

Is there any way to get an air hose inside to attempt
blowing out the swarf from inside the gearbox? Some of those old
boxes had some extra room in them, while others were completely
stuffed.

... If I could blow it out from the bottom
I'd blow the swarf right into the bearing. That wouldn't harm the
bearing if it's delryn swarf, but it'd eventually get washed right
back into the drain hole.

There might be an alternative to teardown; sulfuric acid (sometimes available
as drain cleaner) might attack the plastic well enough to just
rinse a clog away, assuming you can get SOME flow to the blockage.
It won't attack machine parts much, just organics (rinse afterward with your
dirtiest ready-for-recycling oil).

But, takeapart is SO instructive, maybe that's the best longterm solution.