Dropped sump, found metal

Hoogah

Well-known member
Just dropped the sump (looking for the source of an oil leak around the rear main bearing) and found some metal under the baffle at the front that I can’t identify. A couple of the pieces are fairly substantial - the biggest one is around 20mm Long and 5mm thick. Any clues on where to go looking? The engine has been running OK with no odd noises. It has an engine reconditioner label on the side, dating to 1986 (Bud Cheney, Idaho Antique Engines, Idaho Falls, Idaho).
 
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It appears that the lower part of the rear main thrust (washer?) has broken away - circled in red. What would normally cause that to happen?
It looks like I’ll have to pull the engine out (leaving gearbox behind) to remove crankshaft and replace rear main thrust. While doing that, we can also check out the bottom end of the motor.

I’ve also circled the rear main bearing cap plug (green). Does this need to come out in order to check for blockages in the oil tube?

The oil tube has been tacked (blue circle). Do I have to remove the oil tube if I can clear any blockage without doing so, or will removing the cap give me the required access?

I’ve checked out replacement parts for the rear main thrust in the Brattons and Snyders catalogues, and am confused about the options in the attached photo. None of them seem to be a direct replacement for the broken part (red circle)?
It looks like I can choose from either #8960 or #8949, but these look as though they sit ABOVE the crankshaft, whereas the part I need to replace is BENEATH the crankshaft. Or are the photos not orientated correctly?
And where would #8970 go? To use it, I’d have to cut the rear slinger off the crankshaft, according to Brattons catalogue. If so, how does the rear main receive oil?

What do the wiseheads do in this situation?

Extra info:
The broken parts were found in the bottom of the sump, below the dipper tray (in answer to Da Wizard).
We checked the fore/aft crankshaft clearance using a feeler gauge at the front main bearing. It was 0.035”, considerably greater than the recommended clearance (0.007” from memory - the book is at my mate’s house with the car right now). Comments on that?

I would really appreciate your opinions and guidance here, as I am not a mechanic but am trying to understand what I’m looking at and how to fix it. I want to learn and do! I do have a mechanically minded mate helping me (more like the other way around!).

Also, any tips on hoiking the motor out? It has those float-a-motor rear mounts.
 

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I hate to be the bearer of bad news but it looks like you are in for a rebabbitting job. The parts you show from the catalog are not replacements for the front thrust on the rear main. While a skilled shop may be able to fit a replacement rear cap if all other bearing surfaces are ok, most likely there are other problems that will mean a total rebabbitting job
 
If the problem is only on the front thrust, your problem is minimal. The rear takes the load when depressing the clutch, the front has very little load on it. #8949 may be your best bet but will require engine removal and some machining. Not sure what 8960 is/does. I had such a problem but on the rear. I had a race date to meet, so pulled the cap and replaced the rear thrust with flattened copper tubing, it solved the problem and after the race, when I tore the engine down, the tubing looked good. Pull the cap and inspect all that you can see, and go from there. That could be contributing to your leak?
 
I would have the engine rebabbited. In fact, I had a good block rebabbited for what seemed a lot less than what you're experiencing. Cost, $700 US. My center main was cracking. A good time to "Refresh" the motor with whatever else it needs and lap in and adjust the valves.

As far as removing the engine goes, I prefer to take it off the the the flywheel cover and leave the transmission in the car. A stripped down (Starter, manifolds, generator, etc) mod A engine is not too heavy. The manifolds can be left(on the tailpipe) in place and tied back, out of the way. An engine, so lightened, can be pulled out with a small 1/2 ton cable pull. The balance point is the third spark plug hole. You can take a old spark plug, knock the ceramic off it, and weld a hook or a eye to it and thread it into the spark plug hole and lift wit this arrangement. But I don't really like that dependence on the threads of one hole to lift that weight. I made a two hook system (Number 2 and 3 ) spark plug holes. It makes me feel better!
Terry
 
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Hoogah, Real sorry to see that. The same thing 'just happened' to my Town Sedan ~3 weeks ago.

At the Orange County Pancake Breakfast, when I started it to leave, it made a slight knock, but went away right away. Drove it ~35 miles home, no problem. Next morning drained the oil and got metal flakes. Dropped the pan and found metal chunks similar to yours.

I cut open my oil filter and there was not any metal flakes so all the 'shrapnel was confined to the pan.

After discussing with the machinist and a few guys from our club, I think we're going with inserts. Something is going on with the cam also, so it is getting a new cam and lifters.

Must of happened after that last BURNOUT... :rolleyes::rolleyes:Best of Luck with your (unwanted) project. :p:p


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if you take one of the larger pieces does it bend a ways before it breaks---or does it snap off without much bending---like it is brittle
 
Thanks for your comments and photos. This has all been valuable input for me.
Today's job is to pull the motor, and see what the extent of the carnage is! I will update this thread as we go.
 
We pulled the motor this weekend and confirmed some serious babbit issues. The rear main cap has lost much of its babbit and the crankshaft is a little scored under this bearing. We took the cap off the No.4 big end bearing and found the babbit was compomised here too. The camshaft appears to have some (minor?) pitting. The crankshaft feels worn where it passes through the front oil seal.

Before we pulled the motor, we performed a compression test. All cylinders read 78 - 80 psi (dry) and the reading only came up by 2 psi on two cylinders when wet (oiled). This gives me hope that I can confine the rebuild to the lower half of the motor, but what do you guys think about this approach?

As far as I know, the motor is completely standard with no high compression head or other mods. We have a local rebuilder in town who has done a fair bit of vintage work. I am going to ask his opinion tomorrow and will also ask an retired employee of his (who is a friend and fellow club member with a vintage Oakland) to come around to have a look.

Feeling a tad down!
 

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Rebuilding the lower half is where the money is,its cheap to run new pistons and do a valve job,nows the time to check it all. Babbit or inserts its up to you,inserts don't fail from bad tinning or chunk out like that rod..but they are designed for pressure fed/pressure filtered oil engines,not gravity and splash..that being said,they are proven by countless engines to work effectively.Good luck..
 
We pulled the motor this weekend and confirmed some serious babbit issues. The rear main cap has lost much of its babbit and the crankshaft is a little scored under this bearing. We took the cap off the No.4 big end bearing and found the babbit was compomised here too. The camshaft appears to have some (minor?) pitting. The crankshaft feels worn where it passes through the front oil seal.

Before we pulled the motor, we performed a compression test. All cylinders read 78 - 80 psi (dry) and the reading only came up by 2 psi on two cylinders when wet (oiled). This gives me hope that I can confine the rebuild to the lower half of the motor, but what do you guys think about this approach?

As far as I know, the motor is completely standard with no high compression head or other mods. We have a local rebuilder in town who has done a fair bit of vintage work. I am going to ask his opinion tomorrow and will also ask an retired employee of his (who is a friend and fellow club member with a vintage Oakland) to come around to have a look.

Feeling a tad down!



IMV, don't even think about putting 'bandages' in place of any proper routine of R&R, when doing this job !
You will be sick, if something shows later and you remember that is where a penny was thought to be saved. The hard work is done when all dis-assembled. You most likely tour if club member. Don't want to worry when enjoying hobby, eh ! Do what's right, not what's cheap.
 
Hookah,
Here’s my two bob’s worth.
I’d measure the bores to ascertain how much they are worn but unless they are in pretty darned good nick and you can get away with just alone and new rings, I’d go the full Monty. FWIW, that would be inserted bearings. They have been proven to be a long term proposition with the Model A lubrication system. I know of a guy with 50,000 miles on a set going strong. That would likely be many many year’s motoring. I use them on in my outback touring engine.
Oh yeh, I’d install an oil filter at the same time. From what I have been told by people who should know, inserts like clean oil. I use the one that goes on the side cover.
Good luck and please keep us informed.
 
Hookah,
Here’s my two bob’s worth.
I’d measure the bores to ascertain how much they are worn but unless they are in pretty darned good nick and you can get away with just alone and new rings, I’d go the full Monty. FWIW, that would be inserted bearings. They have been proven to be a long term proposition with the Model A lubrication system. I know of a guy with 50,000 miles on a set going strong. That would likely be many many year’s motoring. I use them on in my outback touring engine.
Oh yeh, I’d install an oil filter at the same time. From what I have been told by people who should know, inserts like clean oil. I use the one that goes on the side cover.
Good luck and please keep us informed.

Hey Synchro, I ain’t no hookah! But thanks for your 2/-‘s worth, including the advice about an oil filter. I’ll check them out. Are you in the US yet/still?
Hoogah.
 
I wouldn't call that "Minor Pitting" on the cam. I'd replace it. On used cams, the center bearing is 1.557" as the "no go". It should be 1.559" ideally. Don't buy someone else's old junk cam!
Terry
 
Stipe IB330 is an excellent choice on camshaft (these are new NOT regrind cams).

It will restore lowend torque lost with a regrind and has new spec drive gear for dist and oil pump for less dist backlash.
 
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We've all taken the quick and easy route, and we all wish we had done it right the first time.
I rebuilt my flathead and smiled at what appeared to be a decent clutch, throw out bearing and bearing hub. Less than a year later I was pulling the ****** and replacing those "decent" appearing parts.
I won't ask for a show of hands from those of us who have "taken a shortcut" on a project.
How sweet it will be driving knowing it was done right.
Enjoy the adventure, Chap
 
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