The Ford Barn

Zimmco · 09-02-2014, 07:32 PM

What is the reason that the drain hole on the forward edge of the rear main cap is threaded? Somehow I think this is for a check valve used on some trucks, but am curious why Henry did this on all engines. Is there something else that's supposed to thread in there?

Al

KiWinUS · 09-02-2014, 07:45 PM

A tube screws into it

Ed Pitts · 09-02-2014, 07:53 PM

Here is a pic of the tube. Ed

Kurt in NJ · 09-02-2014, 09:31 PM

since there is no "seal", just a slinger if there wasn't a tube down into the oil blowby would come out the rear main and get oily vapors into the clutch --- it works like the trap under a sink --oil goes down, vapors don't come back up

Mac VP · 09-03-2014, 05:24 AM

We have that tube in stock if needed

Terry,OH · 09-03-2014, 06:06 AM

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For 36 the oil return pipe is longer and may be smaller in diameter that the one shown for the 38 and up engine. Ford would remove the tube when changing oil pumps from the early style to the newer later style due to interference with the pump and did not even install the pipe in some later years. By 38 Ford decided to install them once again. If you find the correct one make sure it does not screw into the cap too far and block the oil return (groves in the bearing) or even touch the crank.

09-02-2014, 07:32 PM	#1
Zimmco Senior Member Join Date: Aug 2010 Location: Phoenix, MD Posts: 133	'36 rear main cap What is the reason that the drain hole on the forward edge of the rear main cap is threaded? Somehow I think this is for a check valve used on some trucks, but am curious why Henry did this on all engines. Is there something else that's supposed to thread in there? Al

09-02-2014, 07:45 PM	#2
KiWinUS Senior Member Join Date: May 2010 Location: Charlotte NC KiWi-L100 available here Posts: 2,963	Re: '36 rear main cap A tube screws into it

09-02-2014, 09:31 PM	#4
Kurt in NJ Senior Member Join Date: May 2010 Location: on the Littlefield Posts: 6,159	Re: '36 rear main cap since there is no "seal", just a slinger if there wasn't a tube down into the oil blowby would come out the rear main and get oily vapors into the clutch --- it works like the trap under a sink --oil goes down, vapors don't come back up

09-03-2014, 05:24 AM	#5
Mac VP Senior Member Join Date: May 2010 Location: Cincinnati, OH Posts: 1,361	Re: '36 rear main cap We have that tube in stock if needed __________________ VANPELT SALES LLC Cincinnati, Ohio Office: 513-724-9486 www.vanpeltsales.com www.classictransmission.com

09-03-2014, 06:06 AM	#6
Terry,OH Senior Member Join Date: May 2010 Posts: 4,751	Re: '36 rear main cap Sponsored Links (Register now to hide all advertisements) For 36 the oil return pipe is longer and may be smaller in diameter that the one shown for the 38 and up engine. Ford would remove the tube when changing oil pumps from the early style to the newer later style due to interference with the pump and did not even install the pipe in some later years. By 38 Ford decided to install them once again. If you find the correct one make sure it does not screw into the cap too far and block the oil return (groves in the bearing) or even touch the crank.