The ram, position selector, and the pump all use packing material; not seals. The packing material is compressed with gland nuts on the ends similar to the construction of household plumbing valve stems on fixtures from the 1960's and older. I believe the packing material I got was aramid, but will need to check...there are many different types and diameters. I have the packaging up in my shop and can hunt for it this weekend if you are interested. The good thing is that all of these areas can be serviced with the ram assembly still in the truck, a surprisingly hassle free repair.
Hopefully this will solve your trucks "marking its spot" issue.
Is this installed in a 1946 civilian 1 1/2 ton truck? I would like to see some more pictures.
I have posted an image of a ram assembly from a 1942 military Chevy dumper. On closer inspection, the PTO output shaft housing looks a little different than on your truck.
