Cotter pin in oil pan

Scott H

Well-known member
What purpose does this serve? Looks like a cotter pin installed in a hole in the bellhousing part of the oil pan on my 1940 v8
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It keeps the hole from stopping up. That would let oil from the rear main get on the clutch plate and make it slip. All '48 back engines had this feature.
Eddie
 
Scott, it is indeed a cotter pin, and its presence was Fords acknowlegement that Fords leaked oil. The cotter rattled to prevent the hole from getting clogged.:)
 
I think I'm confused. I have this same thing on my '35 (motor and trans I believe are out of a '46). What is the purpose of the hole?
 
Make sure that cotter pin stays a little loosey goosey so it can jiggle around in that oil pan hole, otherwise, it can't do it's job. Old Henry knew what he was doing. He would never have wasted a cotter pin.
 
That was a consept used also in some early machinery oil passages before high detergent oils came along. It was called a "wiggle wire". It prevented sludge build up and blockage. That's why it's lose in the hole, it keeps wiggling while you driving, keeping the hole open.
 
Old Henry knew what he was doing. He would never have wasted a cotter pin.

When I started rebuilding my first flathead I saw that cotter pin and thought to myself "what kind of ill boggered job is this?". Then later finding out what it was for.:)

Have to admire all simple mechanical additions. Today there would be an electric/computer sensor that when faulty would cost $200 for the part. Cotter pin/1 part .50cents. :p
 
Don't you people use the search feature? I don't know why I have to repeat everything...sheesh:

Remember those old Murray Fahnestock manuals explaining Ford features in a Question and Answer format??
Here's my take:


Q. Why does the new Ford have a cotter key hanging out the bottom of the bell??

A. Its natural shaking as the car is driven ensures that the hole will not become blocked by dirt.

Q. Why is the hole there?

A. To allow oil leaking from the engine to drain out before it can get to the clutch frictions.

Q. Why does the oil leak so??

A. The leak is provided in order to prevent the formation of rust on the cotter pin.

So there. Skilled engineers design everything as a system.
 
Don't you people use the search feature? I don't know why I have to repeat everything...sheesh

I am a big fan of and frequently use the 'search' function...but sometimes you aren't sure what search parameters to use and when the search returns 15 pages of threads that have nothing to do with what you're looking for it can be frustrating...
 
But at least when you do a search here it includes the model T, model A, early and late flatheads, so there is little chance of missing something. Maybe that's why you get so many returns of threads?

Thanks all for ALL the replys, once again I've learned sumthin' new! :)
 
But at least when you do a search here it includes the model T, model A, early and late flatheads, so there is little chance of missing something. Maybe that's why you get so many returns of threads?

Thanks all for ALL the replys, once again I've learned sumthin' new! :)

Me too...new to flatheads..always wondered what that cotter pin was for..I can assure everyone that mine has no rust on it!

Lane
 
Bruce's answer is the most logical :rolleyes:, but stay tuned, as the cotter key is making a comeback in modern cars.
It seems that while cars no longer "high center" on deeply rutted roads, modern cars must contend with speed bumps, which results in "bottoming out" as bad as in the old days. The oil drain hole in both cases befowls with dirt & crud, for which problem the cotter key is employed to prevent.
Welcome back, Cotter!
 
when the search returns 15 pages of threads that have nothing to do with what you're looking for it can be frustrating...

Keep in mind that searches find every instance of every word in the search, not the combination of them. So, a search for cotter pin would not only show every post with cotter in it but also every post with pin in it, even if cotter wasn't in that post at all. The solution is to search with one key word only, no more.
 
Keep in mind that searches find every instance of every word in the search, not the combination of them. So, a search for cotter pin would not only show every post with cotter in it but also every post with pin in it, even if cotter wasn't in that post at all. The solution is to search with one key word only, no more.

I like the Ebay search better, where you can specify a string of words or use an asterisk as a wildcard in part of a word, or even exclude certain words or phrases by using the (-) sign.

(old, vintage, antique) ford ...will give you any listing that has 'ford' and at least ONE of the other words.

(old, vintage, antique) ford -injectors...will eliminate any posts that have the word "injector" but still give you all the ford listings with at least ONE of the other words

In our example "cotter pin oil pan" would ONLY give us posts pertaining to all four words. But apparently our board doesn't work that way.
 
Thanx Guys for answering the question, this Downunder 'Barner has frequently awoken in the middle of the night wondering what the hell that cotter pin's purpose was.
 
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