I'm wondering what kind of leak I should expect, if any, with a good condition early model PTO in my 9N that I am restoring. I never use the PTO to run anything, but it will rotate when powering the hydraulic pump. I just restore these to show and run around with on tractor drives so have no experience un capping the shaft. I cleaned and installed the PTO (early model) in my s/n 292 and filling it up with oil I decided to see if there was any leakage with the cap off. Removing the cap it was dry. I spun the shaft a couple of turns with my hand and just left it for a bit and when I came back to put the cap on a bit later there was about a tea or table spoon amount of oil that had come out. I figure it is leaking and will have to replace the seal that is held in place by a clip and spring against a bronze washer that turns against the inner housing surface. After thinking about it a bit I'm wondering if this leakage is normal and intended to lubricate the ball bearing carrying the shaft. Any knowledge is welcome before I put out the $50 for the seal.

Fifty dollars for a seal? Not that long ago I replaced the PTO shaft seal and it wasn't anywhere near fifty dollars and the job was easy.

As you said for show only, I would put a sealant on the cap threads and install it. All that will happen is the cap will fill with oil, no external leak as there is no pressure from the differential.