Cotter pin in oil pan?
 

When I was changing oil the other day, I noticed that there is a small hole in the rear of the pan with a cotter pin in the hole, the "horse shoe" part is on the inside. Is this way to keep oil that gets past the rear seal to drain out? It is a '48 engine and trans. Thanks for your help on this.

Re: Cotter pin in oil pan?
 

The cotter key rattles in the hole to keep the hole clear.

Re: Cotter pin in oil pan?
 

I posted this on the Model A board long ago:

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.

Re: Cotter pin in oil pan?
 

Okay guys. Here's the real truth. Ford's have a rear slinger that drains the oil from the rear main back into the pan when running. When you stop your engine the oil at the top of the slinger runs down and through a hole at the back of the rear main that allows the oil to go into the oil pan in front of the firewall. The cotter pin is used to keep the whole clean so the oil can drain.

I've also been told that if there is no oil underneath something on a ford that holds oil. Whatever that something is must be empty.

And I think you'll all like this. I have been told that 75% of all Chevrolets built are still on the road. And 50% of those are on the back of tow trucks.

Re: Cotter pin in oil pan?
 

Actually the cotter pin performs two functions. The first, already noted is to keep the drain hole free of clogging. The second is that it provides a path for the oil to form into drops and then fall rather than spread out all over the underside of the oil pan.

Re: Cotter pin in oil pan?
 

the cotter key is not in the oil pan its in the bell housing to keep the hole open to let oil drain out so it doesnt get on the clutch, lol if it were in the oil pan you would have one hell of a leak

Re: Cotter pin in oil pan?
 

Bruce,
LOL,
I've never heard that one before !
I'll definitely have to remember that for future flathead trivia. :)

Re: Cotter pin in oil pan?
 

Fords and dogs mark their territory.

Or: "if you ain't drippin, you ain't trippin"

Re: Cotter pin in oil pan?
 

Oil spread out on the underside of your old Ford is what stopped the rust from forming. Thank the leaky flathead (and transmission, and steering box, and rearend) for preventing rust pits.

Re: Cotter pin in oil pan?
 

Sorry to dupe, but what if you have about 2 quarts on the floor from that cotter pin?

Re: Cotter pin in oil pan?
 

Then you have a leak in the rear seal area. Depending on the year of the engine it could be from different causes.

Re: Cotter pin in oil pan?
 

It's a '40. Was rebuilt last year. The body assembler only ran it to make sure it was running okay. Then over the winter it leaked. It might be less as it spreads pretty well, but looked like a lot of oil. Do new ones have to get seated in or anything? It hasn't been run very long at all.

Re: Cotter pin in oil pan?
 

It sounds like the rear seal is not sealing properly. May need to drive it a little to see if it is a continuing problem. It the engine is not vented properly it can build up internal pressure and contribute to oil leakage.

Re: Cotter pin in oil pan?
 

Thats been suggested by two others, so I think I'll try that first. Get some running hours on it and see if that seats it. Since it was only run a short time before it was dropped in (like minutes) one suggestion was that it might not have swelled enough with oil and isn't sealing. It might have been over-filled too as it doesn't currently have a filter on it.

Re: Cotter pin in oil pan?
 

If it is leaking that much I would have to ask, how much has it been ran in the spot it is sitting. Might be a drain plug leaking. Sure it is coming from the cotter pin? I mean.. How much can a rear seal leak when not running? Over filling would sure do it too.

Re: Cotter pin in oil pan?
 

Forgot that one!

Re: Cotter pin in oil pan?
 

ford3,

Maybe you've some two-piece oil pans, but most I've seen are one piece and the name Ford gave them was "pan (oil) assembly".

Re: Cotter pin in oil pan?
 

I have owned 4 -V12 Continentals and Zephyrs since 1965, They all had that
cotter pin. All of those engines had the "slinger" at the rear of the crank. If
you bend the ends 90 degrees , at 55-60 mph, it sounds like a cop is after you.
Sorry ! April 1st was 2 Saturdays ago . LOL,LOL, LOL.

Re: Cotter pin in oil pan?
 

It hasnt been run in the spot its sitting. At all. That's what surprised me so much. It's definitely not coming from the drain plug though and if it was coming from higher up on the engine...well, it couldn't drain that much.

I'm wondering if it wasn't overfilled.

Re: Cotter pin in oil pan?
 

The transmission also can leak into that area.. don't ask how I know!