VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 1931 Rear Main Oil Leak

I recenty purchased a 1931 coach and it is leaking a lot of oil from the rear of the engine. I pulled the pan and I don't see anything wrong. The pan end gasket was in good condition. The engine has aluminum pistons so it has had some rebuild work done in the past. The leak is mainly when the engine is running about a drip per minute. I looked in the manuals I have and I don't see a rear main seal or a slinger, there could be a flange on the crank that acts as a slinger I don't know.
I would like to fix this, I'm sure this has been asked before many times.

Please help.

This is perhaps the most frequently asked questions. Do a "rear main bearing leak" search, it should give you a ton of answers.
Good luck..........

There is no seal on the rear main....just an oil slinger on the crankshaft. Make sure that the check ball in the rear main bearing cap is working as it should, and also check the valve cover gasket in the rear to see if it is leaking. As Chev Nut said you can also do a search on this site and you should come up with a lot of information.

:) :grin:

Oil leakage on the rearmost main bearing.

Oil spill on a the rearmost main bearing can be owing to for small autflow a the rearmost nether bearing.
Do i discovered my oil leakage, a i'd mounted a new gearwheel oil pump, a gives important more oil from the old original oil pump, a couldn't run quickly enough backward in sump, so that do i dismantle the the rearmost main bearing pan, and took the freeze plug of, and so that to a hole which was, a was one 6 mm. the drill slanted down, back-and forth.
Do i drilled the 2 holes up to 10 mm. and placed plug in once again, after that zero oil leakage.

Sorry my british, post me a e-mail that shall i try on i can define me better.

Jens,
I think we worked it out that you enlarged the small oil drain-back holes in the lower rear main bearing cap to allow more oil
to flow through them.