VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc oil leak

I have about 1500 miles on a rebuilt 235 engine in my 54 convert it is leaking oil out of the flywheel cover,I suspect the rear main seal.I installed the rope seal and it started dripping from day one,what to do now without pulling the engine,need advise,thanks in advance.

Wish I talked to you before the rebuild. The rope seal needs to be put in properly. I roll them in the groove with a large wood dowel, pressing down firmly. Then trim the ends off flush. Also most modern gasket company's rope seals are not any good. Try to find a new old stock seal. The motor will need to be pulled and crank removed to put one in properly.

Noticed this as well on the low mileage 216. I feel your pain. Ugh.

There MAYBE something you can do to not have to pull the engine. I ASSUME that about 90% of the seals leak if the installer lacks previous experience. Do a SEARCH of our old posts on this topic using the Keyword Search Terms: +rear +seal and use the Display Name Chev Nut.

The amount of fluid leaked is the key with most impossible to stop. Having a 50 cent size leak in a week is a lot different than a 6" one every time you drive the car.

Taking off the oil pan, rear crankshaft cap, using a smaller shim, replacing the bottom rope seal with the right kind, and wedging more in the top sides of the top rope might solve the problem? READ the old posts and ask some more questions if you are not clear on what is posted. Some claim to be able to pull the top rope seal out (with a sneaky Pete) and to be able to install a new one in its place without removing the crankshaft. I say lots of luck!!!

Good luck, Mike

P.S. I BELIEVE THE BEST REPLACEMENT SEAL IS THE OLD VICTOR SEAL STILL AVAILABLE ON EBAY

VICTOR Rear Seal

VICTOR rear Seal

The rope seal was a poor design.

The span of time before it started leaking after leaving the showroom floor is somewhere between immediately and thirty seconds. Not much to start with but leaking nonetheless.

The only thing needed for the pushrod cover, valve cover and crankshaft seal have oil to begin its trek to the earth from whence it came was for the oil to get hot. That is the reason for the short period of time mentioned above.

When there is oil escaping (like a convict out of Shawshank) in an unreasonable time period, as short as it is, is that on a rebuild the mechanic hadn't read Gene's advice on how to best install a seal plus the quality of the seal itself. Even then the difference in time for seeping with a factory installed seal (think new car) and one installed correctly is minimal. Think milliseconds. Time for an Incorrectly installed one is even shorter.

Learn to live with it. If not it will drive you crazy. Get a pan, pail, or pad to put under the car and check the oil often. No need fro oil changes. The car will do it itself. buy Walmart brand oil. The old 216 will not gripe. More expensive oil is only a marketing ploy to make sure your equate expense with efficiency. Nothing more..

Best,

Charlie

I firmly disagree about old 216 and 235 engines leaking when new. We had very few oil leaks and if they did leak when new the owners complained and we repaired them. I see more oil leaks on todays modern cars than we ever had iin the good old days.

Gene,

I suspect your memory is slipping about the good old days.

Firmly disagree or not, from day one the old 216s and 235 oil once it began splashing around was eagerly seeking an escape route and the most guliable part for it to start seeping was the rear main seal.

In order to make the fact about the oil starting to seep by the rear seal, I did take some liberty concerning the amount of time needed. But not much. It seemed that it didn't take no time for it to show up.

I agree with you though about the new ones. I don't want to disagree with you so you win. You know much better than I.

Best,

Charlie

I dont know about the 235 but my 216 doesnt have a rear main seal to leak, only a slinger. Admittedly I havent attempted to start it since a full rebuild to know if it is going to leak or not.
Tony

I just ordered the nos Victor seal,going to give it my best shot,if anything I don't think it could be any worse!

1940 was the first to have a rear seal. If everything is as "new" engines with slingers did not leak.
If you go to other cars makes Chat Sites you will see that leaking rear mains were common for alll cars...........

Stude: Are you sure it is a NOS or REPO seal. Let us know how it worked after install please.

Dick

These are the NOS rear seals I am talking about as most dependable.

Thanks, Mike

There are photographs of new '41 Cadillacs on the showroom floors with towels under the car to absorb the oil leaking from the rear main seal. I suspect the same was true of Chevrolets, since the seal was the same.

BobL

There are photographs of new '41 Cadillacs on the showroom floors with towels under the car to absorb the oil leaking from the rear main seal. I suspect the same was true of Chevrolets, since the seal was the same.

BobL

I have rebuilt three 216 chevys and none of them have a major leak. I am driving a 52 and the only leak is the transmission and it is minimal. In the 70s I rebuilt ford truck motors for coke a cola with rope seals and never got a complaint. They just have to be installed correctly.

I have rebuilt three 216 chevys and none of them have a major leak. I am driving a 52 and the only leak is the transmission and it is minimal. In the 70s I rebuilt ford truck motors for coke a cola with rope seals and never got a complaint. They just have to be installed correctly.

I received the seal today plan on doing the job in the near future should I soak the seal in oil put it in dry or put a light film of oil on it? What is the proper way from experience? Thanks in advance.

Very interesting question. I hope you will get some thoughtful responses. My 2 cents is to recommend "dry" since some say to put a little gasket sealer on the caps were the ropes connect

Good luck, Mike

I use the one made by Best Seal. I have used it on both my 216 s with success. I use the thick Lucas oil additive to lubricate it. For me the secret is to adjust the main bearings to their minimums.