leaking oil from rear main

[don samborski]

New engine....289 cu inch ....leaking oil from rear seal....If to much oil pressure would this cause it to leak?...Pulled Pan and rear main. Seal looks very good, can't see any reason to leak...This was on the first time i started engine..so there is no wear or anything... Crank was turned before installing.

Thanks Don

58 Golden Hawk

[Studeman]

More often than not... the leak is the rear PAN GASKET, not the rear main seal. The rear main is easy to install on a fresh engine- and almost impossible to screw-up.
I have seen the oil-pan gaskets incorrectly installed MANY, MANY, MANY times. Especially if it was attempted in-the-car. I've even heard of people that CUT the rear arched cork gasket because they couldn't get it to stay put when they installed the pan. This is a big NO-NO!

There is a specific procedure to install the pan gasket after the main seal is in there and the rear bearing cap installed...
NOTE: I do not like to use any type of sealer that can squeeze out into the inside of the engine (silicone)...

1) You will find (2) small rectangular pieces of CORK. They are DIFFERENT sizes. If you look at the gap in the block on either side of the rear bearing cap- you will see that one is larger than the other. These CORK gaskets MUST be installed in the corresponding gap. I use Permatex non-hardening sealer to "glue" the cork pieces in. Add a touch of sealer ON TOP of the corks as well...
2) Install the long oil-pan side gaskets- inserting the tabs over the cork gaskets you just installed. I prefer to use contact cement, gorilla-glue, or copper-spray gasket adhesive.... to adhere the gasket to the BLOCK. Be SURE to use the oil-pan bolts to help line the gasket up. DO NOT use any sealers between this gasket and the OIL PAN... except for a dab of sealer in the (4) corners where the pan meets the front and rear cork gaskets
3) The long rectangular cork gasket is made to fit in the groove of the rear main bearing cap. It is NOT SQUARE, one side is WIDER than the other. The NARROW side goes into the groove. Again, I use some sort of adhesive to help hold the gasket into the groove. You WILL find that it appears to be TOO LONG.. but it really isn't. NEVER CUT THIS GASKET in an effort to make it fit better. Instead, get the top and side portions of the gasket seated in the groove correctly- and set the oil-pan on top of it. With constant (but light) downward pressure... begin working the oil pan towards the flange of the block (it sometimes helps to "rock" it over the gasket. You may need to use a small screwdriver to align the gasket with the groove- and to push the ends of the gasket TOWARDS the rear bearing cap. Eventually, you will have the gasket completely in the groove.
4) Once the oil-pan is installed, I like to COAT the outside of the long Rear Gasket with sealer, to keep oil from "weeping" through the cork.
5) The FLAT front cork gasket is installed in much the same way- but it is unusual to have any trouble getting that one to fit well.



Specializing in Studebaker Restoration

[don samborski]

Thanks for the info....i suspected that was the problem....I did look at the rear seals and they look fine....i figured i might be the small cork seals....i will follow your directions reinstalling the pan etc.....Thanks again....Don

quote:Originally posted by don samborski

New engine....289 cu inch ....leaking oil from rear seal....If to much oil pressure would this cause it to leak?...Pulled Pan and rear main. Seal looks very good, can't see any reason to leak...This was on the first time i started engine..so there is no wear or anything... Crank was turned before installing.

Thanks Don

58 Golden Hawk

58 Golden Hawk

[Dirtys Speed Shop]

Good Stuff

[JGK 940]

Thanks, Studeman!

Hmmm... sounds kind of like the tag-line in a superhero comic, doesn't it? Considering every Stude I've ever owned has leaked oil, though, that may not be too far off.

This is the best EXPLANATION of this process I've ever seen. Have just copy/pasted it into a file of its own for future reference, on my hard drive. Hope you don't mind. Will not ever reprint without your written permission.

Keoni Dibelka / HiloFoto
In Hawai'i; on Hawai'i; on the Windward Side
If da salt air never chew 'em up bumbye da lava will...

[whacker]

Everything Ray says is correct as far as the oil pan install goes, but after you do that be sure you are correct about the source of the oil. Be sure to check the distributor gasket and the valve valley cover seals. Check both of the valve covers to be sure they are not leaking at the rear corners. It is even possible that the end of the cam hole "freeze plug" is leaking. It can also be the oil gauge flex tube cross threaded. Remember that oil leaking anywhere at the rear of the engine will come off below the rear seal. The rear seal itself, as Ray says, is usually not the problem.