Look at this Babbitt

[Curly]

I was having some severe oil leakage that just started last week. A friend and I pulled the bearing cap and found the problem. You can see in the picture what the heat did to the Babbitt. It also destroyed the lower cork seal. The Babbitt actually melted and covered the oil return hole. We are thinking the trough that was cut into the cap may have starved the surface of needed lubrication but we wanted to put it on the forum and get others thoughts on this. He said years back this was a modification some were making to reduce oil leakage. You may also notice a pretty severe crack on the opposite end.
Your thoughts on this would be appreciated.

[Russ/40]

Severe oil starvation! How they thought that would work is beyond me. I bet it stopped any rear main leak. LOL

[Joe K]

Bye bye thrust bearing. Interesting mod that TOTALLY violates any establishment of hydrodyamic film in the bearing.

But it seemed to have eliminated the rear main leak?

Any helical groove in the upper?

Joe K

[George Miller]

That bearing never did fit the crank. You can see it was only touching the crank in a few spots. The groove is totally wrong. No oil wells it is time to do it over.

[Jim Brierley]

That bearing was likely intended for a full-pressure system but they didn't put a groove where the oil should enter the bearing, starving the bearing and overheating it. The groove and hole we see was an old method of cutting down on leaks.

[PC/SR]

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That groove and hole to the drain is totally wrong, although some folks do it. Remove the cork (which is wrong too) and you will find the correct drain. The correct groove spirals across the bearing and the block to spread the oil, and there are supposed to be wells at the parting line. Attached I hope is a correct rear main cap.

[Curly]

Originally Posted by George Miller

That bearing never did fit the crank. You can see it was only touching the crank in a few spots.

I think it did fit George, it's just a new engine so it's not worn in yet. Does this sound plausible?

Originally Posted by Jim Brierley

The groove and hole we see was an old method of cutting down on leaks.

Jim, if this is the cause of my melt down, and we think it is, you would think others who tried this method would have had problems as well. Have you heard of others?

[Curly]

Originally Posted by Joe K

Any helical groove in the upper?

Joe K

No Joe. No groove at all in the upper.

The upper Babbitt is in the same condition as the lower. We're going to replace the lower cap/Babbit and the cork seal and see if it works for us. I know it's a risk but it would prevent us having to pull the engine. Do you guys think it will work?

[Joe K]

We haven't seen the upper, but based on the wipe-out of the lower I think you're asking for trouble.

The thrust land on the Model A crank is skimpy enough - which is why they sell brass inserts which offer some more support - and allow correction of exactly this sort of issue which you've developed here (unwittingly)

Better to pull the engine, go back to the drawing board - and do this thing right - and on both upper and lower.

You may be able to use the existing babbit - or have your rebuilder "weld in" babbit to fill the funky grooves and start again. But then again, he may look at the labor and say OTTA THERE - and start again from scratch.

IMHO, pulling an engine is WAY easier than working underneath too.

The roll around stands you can adapt using the straps that come with it are available for small money from Harbor Freight. Usually less than $50.



$45.99 currently.

Joe K

[Jeff/Illinois]

Curly, could you tell us who did that work? If you know? Might save someone else a big headache. PM me if you don't want to say on here, please.

[PC/SR]

You need a groove in the block side too, to spread the oil. Replacing only the cap risks getting the bore mis-matched and out of align. Its a real maybe.
And do not "replace" the cork seal. Remove it entirely. If there is cork on the block side remove it too.There is an aluminum "seal" (which is not really a seal) that fits in the block, Snyder part # A6335. But then again, the rearmost flange on the crank that fits in the groove where the cork is has apparently been removed too, so.....I guess you take your chances and try your luck, or start from scratch as mentioned above.
A correctly restored rear main will not leak more than the proverbial few drops to mark its territory, and some leakage to the rear is needed to lubricate the thrust face. Your thrust face looks really bad probably from lack of that lubrication.
While it is down and open you should check the other caps as well. Maybe they were done right, but better to find out now.

[Curly]

I don't know who did it unfortunately.

The top babbitt surface closest to the cork seal is worn down the same way.

[Joe K]

Where are you? Maybe someone is close and can take a guiding interest?

Joe K

[Curly]

Located in Alaska. We have a strong Model A group up here which I am involved in; I dont know what I would do without them. The truck was restored down in the states to a very high level so we were suprised to see this when we opened it up. I'm sure it's one of those things where they thought they were doing the right thing for the motor. But the end result is a big failure.

[d.j. moordigian]

[QUOTE=Curly;1055775]I don't know who did it unfortunately.

The top babbitt surface closest to the cork seal is worn down the same way.[/QUOTE]

Do you sit at a stop light with your foot on the clutch, in gear? It could
be a lack of free play on the throw-out bearing..

The hole in the cap is too control excessive oil leak at the rear...

[George Miller]

I think it did fit George, it's just a new engine so it's not worn in yet. Does this sound plausible?
__________________________________________________ _______________

It looks to me like it was bored oversize and tapered.

[CarlG]

Hey Curley - - - Update your profile with your location and post a picture of that great looking truck of yours in your avatar!

[Kohnke Rebabbitting]

George is right, that shaft never did fit.

What I see is the babbitt was never peened, at all, or a very bad job of it with a Wilson hammer.

It looks like to me he missed his align bore size, and tried to compensate for it by lowering the cap.

The cracks in the babbitt in the rear main is from not peened, and the shaft jumping up and down, and fractured it.

As many have said, lack of oil, the bearing will open it's self up to get the amount it needs, or burn it's self trying.

We have seen on here many times before, even with oil wells, you need the Diagonal groove to keep wiping the bearing with oil.

You should get a full refund on the babbitt job, don't let him do it over again expecting a different out come.

Ford put those grooves there for a reason!

Herm.

[hardtimes]

Hey Curly,
Curiosity , is your engine plumbed for full pressure of stock oiling system ?

[Curly]

Not plumbed for pressure. Stock oil set up.