TO-20 PTO Seal Replacement

The housing has a shoulder instead of a retaining clip on the front side that the bearing sets against and a c-clip on the backside of the bearing then the seal. No way to get to the c-clip to remove the bearing without first removing the seal. No easy way to drive the seal out without removing the bearing first. Kinda of a catch 22. I did finally get the old seal removed.

The replacement seal is only about 5/16" width so I am thinking about driving it in as far as it will go. Later on when it starts leaking there will be enough room to just drive another one in behind it. Or I could put two in now for a double seal. Is the seal dependant on the oil for some lubrication? If two seals are put in will the back one wear out quicker because it will not be in contact with the oil? Old tractors are sure fun!
Terry G