Flathead oil leak & flywheel ring gear troubles...

Randy

Well-known member
I got my '33 running last Friday. It was last registered in 1953, the last recorded oil change, according to the Veedol sticker in the door jamb, was done on Sept. 4, 1952, by Bill Gasper Associated Service, in Long Beach, CA. Mileage recorded was 67,487 and the odometer now reads 80,696.

While working on some other problems yesterday, I noticed a huge puddle of oil underneath, it had hardly dripped at all over the weekend. It was dripping oil out the hole in the rear of the pan, the one with the cotter pin, so outside the sump area behind the rear pan seal and rear main seal.

Initially, I figured the rear main had just let go after sitting so long and then being put into pretty heavy use. After thinking about it, it didn't make sense as it was leaking sitting still.

I had already changed the oil prior to the first drive, but I drained it again and noticed some sludge coming out. I put the plug back in and poured a quart of kerosene in and let it sit while I worked on some other things, hoping to break down the sludge and get it to drain out. When I did drain it again, more sludge, so I did it again, but with two quarts of kerosene. As soon as I poured the second quart of kerosene in, it began pouring out the hole with the cotter pin.

I guessed that it had so much sludge in the bottom of the pan that the second quart got the level up to the rear pan seal which must be what had deteriorated to allow the leak.

At this point, I realized I had no choice but to pull the pan. I got all the pan bolts out and got it popped loose from the block and front seal, but it would not come down more than about 1/2 inch at the front and less at the rear.

I pried and tried all to no avail, it wouldn't come any lower, it was stuck on something inside. I had noticed that the bottom of the pan was bent up, like it had hit something or someone had lifted it with a jack. I know that the baffle, the back edge of the sump, and the oil pump were all a pretty close fit so I figured something had bent inside whenever the outside got bent and it was jammed up around the pump somehow.

After prying on it every which way I could, nothing helped. I decided that the pan was pretty toast to begin with and much worse after all my prying, so decided I needed to cut a hole in it and remove the oil pump bolt so the whole thing could drop.

I got out my Dad's airhammer and proceeded to cut a hole in the pan close to the oil pump. After several tries, I got the hole to where I could reach the oil pump bolt. I got the bolt out but it still would not drop down. It seemed to be hanging up farther back, like around the flywheel. I cut another hole farther back so I could see back there and that was it, it was hanging on the flywheel! A little prying in the right place and the whole sludgy mess dropped down.

There was a groove worn in the rear sump wall of the pan, in the bulge area for the oil pump, and that groove had worn all the way through allowing any fluids above that level to leak into the flywheel cover area of the pan. I was guessing that the pan had bent in that area from when it was damaged, until I looked underneath the engine and noticed that the flywheel was almost touching the block. Upon closer inspection, I discovered that the ring gear had slid forward on the flywheel allowing it to touch the oil pan. I never heard a thing the whole time I was driving it and it was a pretty deep groove, so I guess it had been rubbing before. Maybe they put this '40 engine and flywheel in it in '53 and heard this horrible noise and quit driving it, beginning it's long hibernation? Who knows. It does seem like an odd coincidence that it only finally wore all the way through these last few days that I drove it.

I took a hammer and tapped on the ring gear while turning the engine over by hand and was able to get it back where it belongs, against the lip of the flywheel. I'm amazed that it started every time and that the ring gear never just slipped on the flywheel. It did start quickly, never had to crank it much, and it probably doesn't have alot of compression.

Anyway, finally to my question. What can I do to get the ring gear to stay in place? I can see where someone used a punch to try and peen the flywheel around it to hold it in place, so someone knew it had a problem or maybe they had just replaced the ring gear or flipped it over.

If I can get it clean and put a few small tack welds on it in a few places, will that work? Will it throw the engine out of balance? Any ideas?

Happy Thanksgiving!

Thanks, Randy
 

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i personaly wouldnt do that because there is a problem there. it was loose when you found it, and as you stated it was loose once before and some one else tried to fix it, i would pull it and put on a good flywheel and ring gear, but i understand where your coming from, thats a lot of work, seeing that the ring gear and flywheel are two completly different metals its going to be hard to get the right rod to weld them together, that being said you have nothing to loose, both probably need to be replaced in the future, i dont thing spot welding them will make a whole lot of difference on the balance if you space the welds the same distance apart and make them as close as you can for size and length, if it doesnt work your just back where you started
 
I have a couple of flywheels that have the ring gear tacked in place- I would use a nickel rod in deferance to the cast flywheel... (Stick weld)... Karl
 
I do not think I have ever heard of such a thing.

I do not think you have anything to loose. I would go ahead and put some tacks, evenly spaced and as close to the same amount of weld as you can. Probably 6 welds about 1/2 inch long should be enough. Worst case, You will have to pull the engine and change the F/W.

You will have to figure out what rod to use as the ring gear is steel and the F/W is cast iron????

Chris
 
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Dril and tap for some small screws, 1/2 in the flywheel, 1/2 in the ring gear, 8 would be enough,.

If you weld you will have to use rod compatable with both metals, the iron of the flywheel, the steel of the ring gear ---then it will be a pain to fix later, and the heat of welding could take the temper from the teeth.
 
In this case,a mig welder will be just fine.We do this all the time on tractors and such.Never had a failure. James
 
I like both of the suggestions above! to add one more, loctite sells a retaining compound such as RC/603. consult your local bearing supply house such as Bearing Distributors.
 
Back in 1965, my 1939 Ford ring gear slipped. My father, a mechanic from the old school, put my car on a lift, pulled the starter and used a punch and hammer to reposition the ring gear to it's proper position. He then used high nickel rod and tack welded the ring gear to the flywheel. Now some 45 years later, it is still in place and has never looked back.
Go for it, welding is a good fix.
 
I would not rely on welds alone .I worked on this very problem this week some one had welded spots 3/4 around the FW ,and they had all broken not the welds but the cast fly wheel around it .there was sever rub marks on the same oil pump bulge. I machined a 1/8 groove in the fly wheel and spotted inside the the ring gear and machined it down so they fitted in the groove .Heated it then hammered it on ,then shrunk it with water,
 

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The car that this was on is 12v volt ,so the starter gives are real punch ,there were remains of starter bendix spring parts in the bell housing as well .I did spot weld as well .
 
Not wanting to override the other suggestions but as I said the welds had broken under them on the cast iron ,This is typical of cast iron .If you are on 6volt then welds on there own may be OK . But if its 12volt through a 6volt starter then you will need to make real sure its good and tight .You could put welds on the inside of the Fly wheel every 2" then grind them away down till you have 1/16 left just a little to tighten things up a bit ,otherwise you will not get it over the FW ,then heat it and shrink it on and tack weld it as suggested .
 
The flywheel and ring have way different reactions to the application of heat. Applying heat to the ring affects the heat treatment of the ring causing it to expand. On the other hand cast iron has to be heated and then cooled slowly during welding processes or it will crack. If you weld you end up with the welds being the only thing really holding the ring with possible cracks in the weld. I would suggest drilling the flywheel for some small high tensile strengh fasteners inserted at the split line of the ring seat joint much the same way as some dragsters hold the tires on the rims. They could be counter sunk or counter bored to prevent clearance problems. At least this would eliminate any heat damage for a problem flywheel installation. Flywheels can have major failure if a crack forms anywhere in their periphery. Proper machining would be somewhat safer than welding in this respect.

Kerby
 
I had the same thing happen on a 8ba. Just tap the ring gear back so it seats all the way on the flywheel and then go around it with a punch and peen the flywheel so the ring gear cant walk off it again.
 
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