I'm only a few years beyond my rebuild, but have always been disappointed that my green Willys leaked.  I pulled the drive train, determined to seal it up better than the first time around.  I was surprised how greasy the shift tower was when I pulled it to drop the tranny.  I decided to decrease the chance that this will leak. I added a seal plate to the rear of the shift rods.  I've seen others do this with some success.  I drilled and tapped the tower (1/4" x 20) so I could hold the plate in place.  I added some RTV gasket maker.



I was missing one of the caps on the front of the shift rods too.  I wanted to get it all back together today, so I was a little bummed.  Turns out, 1/2" copper caps are a perfect fit.  I shortened them, added some Permatex, then drove them in.  A perfectly workable solution...




The jury is out as to whether these steps will help seal it up, but it's a relatively easy approach, so it may be worth a try.

Tim

You may run into a hydraulic lock problem by sealing the ends of the shift rails where they weren't originally sealed. When oil migrates to the end of the shift rails it has no place to go when a shift is attempted. Cut a thin slot in the shift rail so the oil can get back to the transmission during a shift.

Disregard the comment in the pic but here's the underside of an M38 tower.

Unfortunately I do not have a spare M38 tower kicking around and the dozen or so pictures I have of my last M38 tower overhaul offer no clues. I'll be venturing back out to that M38 in the woods I posted about a couple days ago. I'll try and take a look at that one.