[A-Man]

My 1930 Deluxe Coupe has a serious oil leak, which appears to be coming from the rear main area. As I have not tore this "stock" engine down (reported to have been overhauled when I purchased it about 10 years ago), I plan to delve into, searching for the cause. I should comment that the engine did not have a severe oil leak when I purchased it, and has become more severe as time goes by.

I have searched postings on this forum. I believe I have determined the leak to be coming from the rear main area. As I understand there could be many causes for the leak, however, two(2) appear to be at the top of the list - cap clearances on the crankshaft and/or plugged oil tube on the rear main cap.

I plan to remove the oil pan to examine the rear main, and have the following questions:
1) What is the best approach in looking at the oil tube to determine if it is plugged - removal of tube?
2) I also understand that the length of the oil tube into the oil pan is crucial. How is the proper length determine, if I have the oil drained from the oil pan for removal?
3) What is the best/proper way to examine the cap & crankshaft clearances? Ideally, I presume the cap should be removed. Can it be down without removal?

I have been using 30 weight oil. I have examined the oil filter cap and oil filler tube. I have even removed the filler cap(installed nylon stocking hose as a temporary cover) to eliminate/reduce internal oil pressure.

Thanks.