Because I have too many projects and because I suspected that the oil leak issue on my 1936 Plymouth (with A 52 Dodge 230) is a can of worms I hired a good mechanic solve it for me.
My suspicion was that I did not have a simple leaking rear main seal (leak was getting too large).
Upon inspection he discovered that the previous owner added a copper shim at each side of the end-cap. He removed these shims and confirmed that without them it fits too tight. I think that this end cap is from another car (parts bin build?). Anyway, it appears that the leak is caused by the shim creating a gap in the seal fitment.
He is going to check the fitment with some plastigage and get back to me (it could be adjusted depending on where it is too tight - one side or everywhere).
If it cannot be made to fit without machine shop then we are done I and I pull the engine.
Question: Has anyone ever discovered a hack to at least fix this temporarily (knowing that it needs to be fixed right later)?
I have another question. Lets say that i did not have this end cap/bearing fitment issue and I just had a leaking rear main seal.
It appears that it is just about impossible to change the top half of the seal with the engine in the car. If you remove the transmission and flywheel it would be easier but there is not a lot of clearance to get to the three bolts that hold in the upper seal. Even with these things out the crankshaft flange clearance and getting at the top bolt might still be hard.
Here is my question: Do most people just change the bottom half because it is where most of the oil will leak (due to gravity) and wait to change the top half next time the engine is out?