Ok, I removed the 6 bolts and opened the cover. This was actually pretty tough since the plate was glued to the transmission case. Anyway, after carefully hammering it finally came off without any damage, 1 hour later
. Indeed no magic behind the cover .. all parts came out easily (Picture #1)
There was a small problem though. One of the ball bearings had a broken ball retainer (Picture #2) and pieces of metal were laying around in the oil. So went to the tractor shop, bought new bearings and replaced the old ones.
The PTO seal which I'd ordered had also arrived so now I could actually see the thing (Picture #3). The rubber seal indeed has an attached metal ring, as described by JKP (note that this is different from the pictures that some webshops show as the PTO seal).
Assembling everything was pretty easy. Pressed the new seal into the back plate. Inserted the PTO shaft (added some grease so the rubber does not immediately get damage). Moved the other shaft back in place. Installed a new gasket. Closed the back plate with the 6 bolds. Added new transmission oil. Etc ... Pictures #5
So ... what have I learned .... the PTO seal can actually be removed without opening the back cover. It is pretty simple: there are 2 notches in the circle on the back plate (the 2 indentations that are lined up horizontally). Put a small screwdriver behind the metal ring and the seal should come out .. Picture #4
As said above I went a different route, opened the case and knocked out the seal from the inside. But I do not see any reason why this cannot be done from the outside. BTW, the guy at the tractor shop confirmed .. just drive the front wheels of the tractor into a ditch (plenty of them here in Holland
) and remove the seal with a screwdriver.. no need to drain the transmission oil ... just a 5 minute job, he said.
But I am happy that I did open it and could replace the damaged bearing.
And certainly an interesting first exploration into the interior my new (1977) Kubota!