I've searched the forum for some mention of my specific problem and didn't find one. Forgive me if there is and I missed it.

I have an 85 power ram 50 with the diesel and the km-145 trans and case. I have a persistent oil leak at the front output shaft. Three different folks at different times have replaced the seal to no avail. I was one of them so you could say at least two of the people knew what they were doing. The universal joint at the transfer case end of the drive shaft was replaced in the hopes that movement of the joint was the culprit. I'm at a stopping point on where to go from here. I've read that some vehicles have a vent on their cases, but I couldn't find one on mine. The shaft did not have any irregularities on the seal surface that I noticed either. The leak occurs when the truck is parked also. The wrong seal is an option, but three folks getting it wrong seems unlikely, plus, when I did it, the seal squeegeed the shaft tightly (I apologize for the imagery). Does this problem ring a bell and recall a simple solution to anyone?

Any input would be appreciated.