Thought I would run this by the 3A team to see what you think.
I love my green Willys, but it had two flaws. The TC whined like a 5 year old at bedtime. And number two, I�ve never been able to solve my rear main seal leak.
I rebuilt a replacement TC this past spring. I upgraded to a TC with a 1-1/4� intermediate shaft. This case runs much quieter at high speeds, so now I�m down to the rear main seal leak. This drives me nuts. Those of you that know me personally understand why I don�t like this. For those of you who don�t know me, I�m the guy that scrubs my undercarriage after a week of Willys trail adventures.
This is a GPW engine. Tolerances in that era were not as precise as they were during later 3A production, so I�m already fighting an uphill battle. Short of pulling the crankshaft and having this race repaired, I have tried every conceivable approach to eliminate this flaw. I have installed 5 different seals and used just as many different techniques. Nothing stops the leak.
What I have noticed over the years is the rear main won�t leak unless I push the engine to its extremes. The oil pressure on this engine is around 23psi at warm idle and mid 50s during warm acceleration. It's much higher during warmup. (40psi at cold idle) This is pretty high for an engine like this. I believe this high pressure pushes the oil out of the weakest point. In my case, the rear main seal.
I am considering putting a weaker relief spring in the oil pump so to reduce the overall engine oil pressure. I know�crazy�right? We are always trying for higher oil pressure. My thinking is this would possibly reduce the pressure on the rear main seal and thus reduce my oil loss. Or am I thinking about that relief spring in the wrong way? What do you think?
This is a photo of one attempt to stop the leak. In this case, I compressed the filler dowels and let them set up in a bath of RTV sealant for a few days. The blue you see is what squished out when I compressed the dowels.

