VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1940 - Oil Leak

Yesterday i went to the German Tüv, by the way passed without Problems . Everytime when i stop with the car a look under it is my first way to do. Because in the past i had only one time a big Oil spot under the car, didn´t know from where. Yesterday again and now i could see, the oil comes from the hole in the pan under the clutch. Seems to be the bearing seal from the Crankshaft? What shall i do? Think there is a upper and a under seal. Is the under seal in the Oil Pan? To replace the upper Seal caused a lot of work..

My 1951 216 in my truck leaked badly from the rear main seal. I replaced it twice and it lasted about 200 miles both times. The third time I replaced the main bearings because the old ones were worn. The new seal does not leak at all after 30,000 miles.

When I did the seal I removed the transmission and dropped the crankshaft a bit. The big challenge was getting the original upper out. I had to use a broken coping saw blade to break the bond between the seal and the block.

I used an NOS type seal. There is a new type sold by Best Gasket that seems to preform well.

First make sure it is the rear main bearing. A rocker arm cover or push rod cover leak can cause the oil to drip into the flywheel cover....and drip out of the hole.
Also the pivot arm plugs on the fuel pump can leak oil.

Will check this, but at the Moment i don't
unterstand how. Must check the manual to understand
Which way the oil could go.

Rarely a road draft tube will clob causing undue pressure in the crankcase which in turn will cause a seal leak. Have not had the problem with a bowtie but my folks 38 Buick had the problem. As I recall there was a metal screen in that tube that plugged. Of cours maintanence had nothing to do with it. My dads idea of taking care of a car was to take it to Sears Roebuck for the discounted spring oil change.

Alligator,

Forget all the wild speculation. It's the rear main seal.

On the old 216s, they began to leak within the first block after leaving the dealership. Did too. Well, seep anyway. That is the reason for the hole in the flywheel/clutch pan. See?

There is no fix for this ailment. The only difference between a new engine/freshly rebuilt one, or the correct replacement of the seal with a good one, is just a matter of time and milage. Milage because the seal will wear enough to let some oil seep by in less than a mile and time because the oil will seep by whether the car is started or not. Will too.

What must be done is to put a shallow pail/bucket under the car until the faster hot oil has stopped dripping and the cold oil starts seeping. The pail/bucket can then be removed and replaced with a Huggie or nappie if you're in the British isles. (tie a string to the nappie for easier removal) There is no other way to handle the perpetual problem. Until you accept this you will chasing you tail until the supply of oil has been completely gone from the face of the earth. Will too. Accept what you can't change. You'll then be much happier.

Don't replace the seal. Buy a shallow pan and switch to a bucket when the problem gets worse. Do not park in private driveways. Park on the street or other public parking areas and walk or use the nappie. Learn to toss it under the car with just a flick of the wrist. Don't let go of the string too soon.

BTW: Pay no attention to Old216. His claim begs realism. He may be dreaming. His car probably hasn't been started for 30K miles. He likely tows or trailers it everywhere and still counts the miles. Or else he's pulling our leg. Also, he's from

The thing that made the difference for me was the clearance on the main bearings. I adjusted them to absolute minimum and it was almost to stiff to start. After a bit of running it was fine. The failed seals were all pounded flat because of the loose bearings.

Hi Chalie,
does it make sense to change only the seal in the oil pan? Think that helps a little bit? The pan is installed and in the Trunk lies a carton to save the private driveways

Like Charlie said ...they will leak ..............I replaced my lower seal 2 times and compessed the upper seal both times, as Gene suggested as a possible fix. Both times it stopped the leak for around a 100 miles ...then drip dip drip again ......get used to it and forget it . carry some cardboard for private drives ....add oil when needed and drive the car and enjoy !!

Unfortunately, German laws prohibit dripping oil. To get your license plate renewed you have to go through a rigorous inspection. Alligator must do his best to eliminate the problem, following the above tips might solve his problem. If they don't then he has to look carefully at replacing the rear seal. Fuel pumps can also leak oil as well as the timing gear cover so carefully looking things over is a must.

Alligator do you know the history of your engine and when it was last rebuilt? If you do decide to replace the seal I would find an original asbestos one. They are hard to find, but I should be able to help you. I also think I would call Germanchevy for advice and do an Advanced Search to see what others have done. Check out the following post:

rear main rope seal

Good luck, Mike

What about bolting a drip pan under the engine compartment? Fabricate it well with some room for a puddle and a drain plug, and paint it to look like original equipment.

Dean

Hi Mike, thanks for the link. Don't know about history of the engine.Next step would be to see were the oil comes from. At the moment I have no desire to change the seal.
Dean, seems to be a good idea. My plate is now brand new and i should take care the next two years not to leak on the street in public - whoever I do this :-)

For getting past inspection you can always tape some absorbent cloth on the inside of the flywheel coverplate over the drain hole and remove straight after..and yes I am ashamed to say I have done this (hope no one from the DMV is reading this..

Rustaholic.....your idea is really great ! someone should fabricate something .....I`d buy one !

The thing we tend to forget with a leaking rear seal is how it contaminates, with oil, the clutch, pressure plate, flywheel area, leading to what we refer to as clutch chatter. The same guys who think it is okay to live with a puddle of oil are also saying a little jerkiness when you release your clutch peddle is also okay.

Putting a diaper on is masking one problem for another. Leaving the flywheel cover off would atleast protect the clutch area from some of the misting oil, and might make it easier to confirm where the leak originates.

Good luck, Mike

The easiest way I have found to locate the leak, remove the clutch cover and thoroughly clean and dry all that you can including the rear of the rocker and side covers. Then go for a 20 or 30 mile drive, this will leave an oil trail (the highest point of oil is the leak).
Tony

Now for the First Time fixed the Problem with German "Ingenieurskunst"
Let Pictures speak:


Think four Magnet´s will fix the pan - it´s the bottom from a First Aid box - under the pan.
First testdrive is on Sunday to US Car Meeting

Looking good! I think you need to get a patent for the design.

Cheers, Dean

Goodness me Alligator... if it leaks that much you may want to fix the leak mate..at least you can pore it right back in :-o

Sophisticated German engineering at its best!

The leak isn´t so big I hope, will see on sunday and report how much. But wanted to enclose the pan so the Oil does not splash unter the whole bottom by the driving wind. And, Hey, it is a "First Aid" Box!

Hi everybody, hallo André,
Yes, indeed, german laws are hard and for the ingeneers who have to do the inspection to give you the number pate sticker which allows you to drive two more years all vintage car fun is over if they are under the car and hot dirty oil is dropping at their neck while inspecting everything...
There might be many reasons where and why an old car may loose oil. The solution is always the same. Clean all and everything and find out where it is coming from. Step two is to repair anything as long you have a clear target to fight against.

If the point to give up is coming up, find a detour called "plan *B*". My previous 1931 did leak much without a concret defective failure. It was just normal for a car in 1931 to leak.
My *plan B* was a big pan under engine and tranny to catch all lost drops and to drain it weekly. Engineers at inspection were happy as well my neighbours with their clean sweeped parking areas and I could sleep quiete well.

So, finally, André, your idea of a box catching the drops is perfect. It will allow you to sleep well and to create solutions for a repair if the time is coming for.
My 1940 is leaking some drops just sometimes at the tranny, exactly where is the lock pin for the reverse gear.
Bad, old construction, must just be accepted, nothing else.

Old cars will always bew old cars, thats it.

Stefan Germany (Bad Reichenhall)

Hi,
found a gasket-set in my garage, it is from Chevsofthe40´s.
The set is original from Best Gasket including the rear seal. But this is rubber and the wrong one, doesn´t fit at 40´s i mean?
Where do the Cork Rings come?

Cork rings by 6 ?? side plate .. spark plugs

Andre,

You should try to get a rear seal that is the old fashion one made with asbestos in it. They were used for the model years 1940-1958. One source is Gasket City in Hamilton, Ontario, in Canada. The phone number is 1-888-335-4686. They can also be found occasionally on ebay.

You should deal with your overheating issues first because if you find there is extensive buildup of rust deposits in the head and block then I would pull the engine and deal with the rear seal leak with the engine out of the car.

I do have a set of original rear seals that I would sell you. Here are some pictures of these seals.









Good luck, Mike