The Ford Barn

Stage1gs · 06-15-2023, 08:58 PM

Hi everyone.. My model a was leaking a bit of oil out of the rear pan gasket so I dropped the pan and replaced the seals. I didn’t do it right and need to redo it, as it leaks more now than before.. When my engine was rebuilt with insert bearings, they tig welded the rear main oil drain pipe to the cap. The pipe is loose in the cap, and you can feel the pipe wiggle when you touch it.

If this pipe is loose in the rear cap, would that cause oil to leak out the back of the engine? The end of the pipe is in oil, but if the pipe is loose, it seems like this would be a problem.

Pamodelaroadster · 06-16-2023, 06:42 AM

Yes, I think it would cause a leak

jack backer · 06-16-2023, 06:54 AM

The rear main bearing is set to a clearance, there is no positive seal at the rear main bearing cap. When that clearance is exceeded the ability of the drain to handle the oil flow is compromised, and your rear main bearing will leak.

Stage1gs · 06-16-2023, 05:42 PM

I agree with that.. my question is.. if the oil drain tube is loose at the rear main bearing cap, Will that cause more oil to leak out the back?

jack backer · 06-16-2023, 05:48 PM

No, as long as it in place it shouldnt

Chuck Sea/Tac · 06-17-2023, 02:07 PM

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Are you sure it’s open? ie: not partially plugged with weld, or too far into the cap.
Are the oil reliefs in the bearing correct. They shouldn’t go the outside edge. Also what is your clearance? The shims go up against the journal. And lastly, how much fore and aft play do you have in the crank. You can have someone step on the clutch, while you watch the crank pulley.

ModelA29 · 06-17-2023, 03:57 PM

Welding steel tube to cast iron cap = bad idea.
Originally they were threaded in. If the threads are stripped you could braze it in.
Since your engine is inserted you don't need to worry about melting the babbit out when you fix it.

Stage1gs · 06-17-2023, 05:55 PM

All good points.. I have to pull the pan once more to fix my oil leak, so I will check all your recommendations I will also pull the rear main cap to fix this, and check the clearance. Also need to check the lateral movement in the crank.. hand.t considered that.

Do inserted engines use shims for clearance? Guess I assumed they didn’t but could be wrong.

Phil Brown · 06-18-2023, 01:24 AM

No shims in an inserted engine

06-15-2023, 08:58 PM	#1
Stage1gs Member Join Date: Nov 2014 Location: Grant, FL Posts: 37	Cracked Weld On Rear Main Oil Drain Hi everyone.. My model a was leaking a bit of oil out of the rear pan gasket so I dropped the pan and replaced the seals. I didn’t do it right and need to redo it, as it leaks more now than before.. When my engine was rebuilt with insert bearings, they tig welded the rear main oil drain pipe to the cap. The pipe is loose in the cap, and you can feel the pipe wiggle when you touch it. If this pipe is loose in the rear cap, would that cause oil to leak out the back of the engine? The end of the pipe is in oil, but if the pipe is loose, it seems like this would be a problem.

06-16-2023, 06:42 AM	#2
Pamodelaroadster Member Join Date: Feb 2022 Location: Mill Hall, PA Posts: 46	Re: Cracked Weld On Rear Main Oil Drain Yes, I think it would cause a leak

06-16-2023, 06:54 AM	#3
jack backer BANNED Join Date: Mar 2022 Location: Chenango Bridge NY Posts: 433	Re: Cracked Weld On Rear Main Oil Drain The rear main bearing is set to a clearance, there is no positive seal at the rear main bearing cap. When that clearance is exceeded the ability of the drain to handle the oil flow is compromised, and your rear main bearing will leak.

06-16-2023, 05:42 PM	#4
Stage1gs Member Join Date: Nov 2014 Location: Grant, FL Posts: 37	Re: Cracked Weld On Rear Main Oil Drain I agree with that.. my question is.. if the oil drain tube is loose at the rear main bearing cap, Will that cause more oil to leak out the back?

06-16-2023, 05:48 PM	#5
jack backer BANNED Join Date: Mar 2022 Location: Chenango Bridge NY Posts: 433	Re: Cracked Weld On Rear Main Oil Drain No, as long as it in place it shouldnt

06-17-2023, 02:07 PM	#6
Chuck Sea/Tac Senior Member Join Date: May 2010 Location: Between Seattle & Tacoma Posts: 2,360	Re: Cracked Weld On Rear Main Oil Drain Sponsored Links (Register now to hide all advertisements) Are you sure it’s open? ie: not partially plugged with weld, or too far into the cap. Are the oil reliefs in the bearing correct. They shouldn’t go the outside edge. Also what is your clearance? The shims go up against the journal. And lastly, how much fore and aft play do you have in the crank. You can have someone step on the clutch, while you watch the crank pulley.

06-17-2023, 03:57 PM	#7
ModelA29 Senior Member Join Date: Sep 2022 Location: SoCal Posts: 614	Re: Cracked Weld On Rear Main Oil Drain Welding steel tube to cast iron cap = bad idea. Originally they were threaded in. If the threads are stripped you could braze it in. Since your engine is inserted you don't need to worry about melting the babbit out when you fix it.

06-17-2023, 05:55 PM	#8
Stage1gs Member Join Date: Nov 2014 Location: Grant, FL Posts: 37	Re: Cracked Weld On Rear Main Oil Drain All good points.. I have to pull the pan once more to fix my oil leak, so I will check all your recommendations I will also pull the rear main cap to fix this, and check the clearance. Also need to check the lateral movement in the crank.. hand.t considered that. Do inserted engines use shims for clearance? Guess I assumed they didn’t but could be wrong.

06-18-2023, 01:24 AM	#9
Phil Brown Senior Member Join Date: May 2010 Location: Santee Calif. Posts: 515	Re: Cracked Weld On Rear Main Oil Drain No shims in an inserted engine