Rear Main Drain Tube

Lembomw

Lembomw

Senior Member
I have a massive oil leak in the ’30 Tudor that I purchased in February. Based on advice from this forum I purchased gaskets to replace the pan, valve cover and oil return tube since the car had been sitting for 10 – 15 years. I dropped the pan today and (due to previous posts I would not have known that it existed) discovered that there is no rear main drain tube. Hola….maybe this is the problem. There are no parts of it in the rear main bearing cap or the pan, no evidence of one ever being there. From what I have read in prior posts, these drain tubes fall out on a regular basis. I am ordering one from Snyder’s tomorrow. Is there any particular trick to keeping them so they will not fall out of the rear main bearing or will just screwing them in be sufficient. Thanks, Mark
 
If yours is not in the bottom of the pan it was never installed. Some old timers believed the tube could be left off to keep leaks down. Works, HUH? I have seen them cut off at all lengths and left off completely. If the threads are good you can use some JB weld and glue it in place or remove the cap and spot it with a mig welder. I immerse the cap in a pan of water when I do this to keep the babbitt cool. Makes for a good time to check the rear main condition.
 
Bear in mind there are 2 sizes of pipe, 5/16" and 3/8". The 5/16 was installed in the 28/29 engines The 3/8 in 30/31. But the engine and/or the main cap may have been changed in the past.
 
You should check for a clogged oil passage while you have the bearing off. Hold it horizontal and sqirt some oil in the collector groove and it should drain out easily. If it doesn't you may have to remove the galley plug and clean it out.
 
Thank you gentlemen. If I remove the cap so I can check the oil passage what to I torque the nuts to when reinstalling. Are there going to be any shims under there? I have not done this before so just want to know what to expect and look for and know how to put back together without creating additional problems. I am not sure I want to spot weld the return tube to the cap. I have a small TIG welder but really not very good at using it yet. JB Weld is probably the way I will go.
 
JB Weld works fine. The drain isn't a pressure fitting. I used it on my return tube without any hesitation. You should see shims in there and if you don't want to go any further into the engine, just make sure that they (shims) go back in the order they came out on the same side. I just finished my B block and torqued the mains down to 80lbs. Per LA's book.
Hope this helps, Pete
 
Just to add to this thread. I just replaced the pan gaskets and seals on my 29 and soaked the cork overnight, left it long for a tight fit etc. When I went for a test hop, I still had a leak. Checked the oil and after driving for about thirty miles, no leak. None. Is it normal for the rear seal to soften and seal after being driven a short distance?
No, it's not out of oil!
 
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