The Ford Barn

Gwill65074 · 04-14-2022, 01:26 PM

Can anyone tell me how hard it is to replace the rear main seal on my Tudor? I've checked the pan bolts and they are snug so I think it's the upper piece that's leaking.
Thanks

rotorwrench · 04-14-2022, 02:30 PM

The OEM set up in an integral slinger ring on the crank that runs in a groove that's in both the block and the rear main cap. There is a drain tube to the groove that directs oil back into the oil pan reservoir. If the tube falls out or gets plugged it can be problematic. The rear oil pan seal can leak. The rear cam bearing can also leak if the rear flange gasket it deteriorated.

nkaminar · 04-14-2022, 03:02 PM

Normally the rear of the engine starts leaking when the rear bearing clearance gets excessive. The slinger and tube cannot handle he increased oil flow. The fix is to remove the pan and check the clearance at the rear bearing. Use plastigage and adjust the bearing as needed. Check that the tube is clear. While you are in there check all the other bearings.

Added Info: The rear bearing can also leak out the sides of the bearing where the cap mounts to the block. Use some kind of sealant there that can be removed at a later date.

The red book, Model A Mechanics Handbook, Volume 1, gives detailed instructions on all things mechanical for the Model A.

Gwill65074 · 04-14-2022, 04:45 PM

Sounds like more than I can do, thanks guys.

Synchro909 · 04-14-2022, 05:00 PM

Quote:

Originally Posted by Gwill65074

Sounds like more than I can do, thanks guys.

Is here a Model A club in your area? If so, I suggest you join it and talk to the other members about your problem. I bet most of them have had the same problem at some time and will know how to fix it or at least who can.

Gwill65074 · 04-14-2022, 06:57 PM

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Thank you

old ugly · 04-14-2022, 07:58 PM

Quote:

Originally Posted by Gwill65074

Can anyone tell me how hard it is to replace the rear main seal on my Tudor? I've checked the pan bolts and they are snug so I think it's the upper piece that's leaking.
Thanks

make sure you have adequate crankcase ventilation. check your filler cap and filler tube to make sure they are clear of any obstructions. needs to be open.
if it is plugged that rear main will leak like a siv

bobbader · 04-14-2022, 08:13 PM

The short answer is ................. there is NO rear main seal to replace. The part that is in catalogs listed as a "rear main seal", has no sealing fiber or rubber lip seal as we are used to in modern engines. It is, instead this semi circular insert that goes into the upper rear main bearing housing. And, for the novice (or even the "old hand), this is not a simple task.

As someone else suggested, take a long hard look at the center gasket at the rear of the oil pan. But, if you do not see a definite trail of oil from that area and instead you do see a trail of oil out of the hole in the bottom of the flywheel housing, your rear main bearing cap might need the adjustment others have mentioned. Study everything you can about this procedure before attempting it.

Good Luck. Bob Bader

Gwill65074 · 04-14-2022, 09:11 PM

Thanks guys, I really appreciate the help from everyone.

04-14-2022, 01:26 PM	#1
Gwill65074 Senior Member Join Date: Mar 2013 Location: Blue Springs, Missouri Posts: 196	Rear main seal replacement Can anyone tell me how hard it is to replace the rear main seal on my Tudor? I've checked the pan bolts and they are snug so I think it's the upper piece that's leaking. Thanks

04-14-2022, 02:30 PM	#2
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: Rear main seal replacement The OEM set up in an integral slinger ring on the crank that runs in a groove that's in both the block and the rear main cap. There is a drain tube to the groove that directs oil back into the oil pan reservoir. If the tube falls out or gets plugged it can be problematic. The rear oil pan seal can leak. The rear cam bearing can also leak if the rear flange gasket it deteriorated.

04-14-2022, 03:02 PM	#3
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,903	Re: Rear main seal replacement Normally the rear of the engine starts leaking when the rear bearing clearance gets excessive. The slinger and tube cannot handle he increased oil flow. The fix is to remove the pan and check the clearance at the rear bearing. Use plastigage and adjust the bearing as needed. Check that the tube is clear. While you are in there check all the other bearings. Added Info: The rear bearing can also leak out the sides of the bearing where the cap mounts to the block. Use some kind of sealant there that can be removed at a later date. The red book, Model A Mechanics Handbook, Volume 1, gives detailed instructions on all things mechanical for the Model A. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past. Last edited by nkaminar; 04-14-2022 at 07:31 PM.

04-14-2022, 04:45 PM	#4
Gwill65074 Senior Member Join Date: Mar 2013 Location: Blue Springs, Missouri Posts: 196	Re: Rear main seal replacement Sounds like more than I can do, thanks guys.

04-14-2022, 06:57 PM	#6
Gwill65074 Senior Member Join Date: Mar 2013 Location: Blue Springs, Missouri Posts: 196	Re: Rear main seal replacement Sponsored Links (Register now to hide all advertisements) Thank you

04-14-2022, 08:13 PM	#8
bobbader Senior Member Join Date: May 2010 Location: Huntington, NY Posts: 271	Re: Rear main seal replacement The short answer is ................. there is NO rear main seal to replace. The part that is in catalogs listed as a "rear main seal", has no sealing fiber or rubber lip seal as we are used to in modern engines. It is, instead this semi circular insert that goes into the upper rear main bearing housing. And, for the novice (or even the "old hand), this is not a simple task. As someone else suggested, take a long hard look at the center gasket at the rear of the oil pan. But, if you do not see a definite trail of oil from that area and instead you do see a trail of oil out of the hole in the bottom of the flywheel housing, your rear main bearing cap might need the adjustment others have mentioned. Study everything you can about this procedure before attempting it. Good Luck. Bob Bader

04-14-2022, 09:11 PM	#9
Gwill65074 Senior Member Join Date: Mar 2013 Location: Blue Springs, Missouri Posts: 196	Re: Rear main seal replacement Thanks guys, I really appreciate the help from everyone.