VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Leak coming from timing chain cover

I have a leak that only occurs after the engine stops running. Oil comes from around the harmonic balancer shaft persumably past the slinger through the timing chain cover. No oil noted when engine is running.

The drain hole from the timing chain plate through the front main bearing cap into the pan appears to be clear. I have checked the clearance of the front main bearing cap and it is within limits (.001-2).

I have installed a new higher output oil pump but once the engine heats up the oil pressure sits around 9 psi, well within limits.

The key clue seems to be that the leak occurs only after the engine stops running suggesting the drain hole back thru the main into the pan is not able to accomdate the oil build up within the timing chain cover. Jim

This is a recurring problem that is ask frequently. Your leak is the front timing cover. There is about an inch of space under the crank shaft that is left with oil after the engine is stopped. After all the oil that can be returned to the crankcase the remainder sits in this space.

The solution is to remove the timing cover. Insure that the timing plate is completely clean and dry. Insure the timing cover is also cleaned and dried. If there is any distortion at the bottom it must be straighten. Use a new gasket. Coat both sides with spray on gasket sealer in the golden can. Do NOT over tighten the screws for the cover. Reassemble and test drive.

Unless I misunderstood your response it looks like you are suggesting that the oil is coming via the seal at the bottom of the cover. This is not the case, it seems to be coming from the center hole that accomodates the harmonic balancer shaft. I must have a pound of RTV on both sides of the seal all away around the cover. Jim

That amount of RTV is definitely a bad idea. If you have to use RTV, then only a very small smear of the stuff is necessary.

Check the suggestions I gave you. Believe me, the oil is leaking as described. Now you need to remove ALL RTV and hide the tube. Clean everything up and reseal as recommended.

Will do, and thanks. Jim

Ray:

No luck, saw no evidence of oil coming past gasget, oil defintely coming through crank hole. I may have the answer but will have to reassemble to determine. The timing chain cover is from a 1934 engine and is slighly different in depth...front to rear compared to the '29-'32 cover. It is possible this could affect the outcome.

Jim

If it is coming from the crankshaft hole it will be unusual. If it is from the crankshaft hole it would leak while running and not leak when stopped.

If it were mine I would remove a shim or two from the front main bearing and see if this makes the engine more difficult to turn-over by hand (with the plugs out). If you are using plastigage the .001" reading may not be accurate and I would go back to the 1932 shop manual instructions for adjusting main bearings. Also the weight of the carnkshaft must be supported when using the plastigage. If the lower main is supporting the weight it will crush the plastigage.
My thoughts are too much oil is passing by the front main bearing. When the engine is running the slinger is tossing the oil aroundbut when the engine stops running it settles at the bottom and fills the lower part up to the balancer hole until it drains down.(and out)
I would also suggest getting a 1929-32 cover and gasket because both have a different part # than the 1934.

I've taken the pan off four times. Does anyone sell pan gaskets by the dozen? The good news is I'm getting better at it. A related question. When I drive the harmonic balancer back so that it makes contact with the slinger and the crank, the harmonic balancer pully sits well behind the other two pullys. Is it necessary to have it flush with the crank and in direct contact with the slinger. Could this in any way be related to my problem? Also, by using the "correct" timing chain cover, when the balancer is driven back flush with the crank, the balancer rubs the timing chain cover. Advice please.

There is another post regarding the Harmonic balancer about 10 post ago,
You may have a 1930 balancer which did a spacer. 1931 did not have a spacer.

When I rebuilt my '30, I noticed the gap between the front pulley hub and the timing gear cover. I took the pulley and the cover to a local machine shop and had them install a seal in the cover. They turned down the hub enough to fit the seal and smooth the hub. When I reinstalled the pulley and cover, I left the cover loose untill I got the pulley installed to allow the seal to center itself on the hub. I haven't driven it a lot, but so far no leaks.

ArtM

The distance from the block to front of the timing cover can be the problem. If the slinger on the front of the crank gear does not overhang the cover then oil will leak past it. The slinger needs to extend further out than the hole to sling the oil away from the hole.

And when everyhting is as it should be they will not leak - with no seal.

And, it is not a timing "chain" cover since no timing chain is used.

new dog forgets old tricks

Have you also checked to see if the oil nozzle is in place , or is it missing? It reduces the ammount of oil in the front timing cover by acting as a restrictor. it is shown on page 39 of the 1931 manual.

Have new theory. When using plastic gage, noticed less clearance towards rear of bearing cap than towards front. Also notice when one of two bearing cap bolts put in, there was a slight binding akin to a slightly bent bolt...however bolt was straight. Am beginning to suspect that some how the bearing cap has become warped and oil is escaping from front into timing gear cover. Now plan to follow advice of one of the commentators and have a machine shop put in a seal. Jim

Am curious as to how the machine shop installed the seal? Did they attach it on the outside, center or middle of the cover, and how was it attached. Also noted your comment regarding not tightening the cover until after seal centered itself. Given the fact that the three lower bolts screw into the cover and therefore are relativly fixed, how did that help with the centering? Jim

Your idea of installing a seal is a great one. It would also solve my problem. I also have oil coming out of the timing gear cover (32 coupe)and I have checked clearances, oil nozzle position,etc. I f you can provide a shop phone number or how the seal was installed, it would be greatly appreciated by us "oil leakers". Regards; HotPockets

If a seal is installed the area on the balancer would need to be polished as it is not designed to have a seal riding on it.

That can be done. How the seal was installed is the mistery. Hope to hear from the lucky guy that had it done. Rgds. HotPockets

I have the cover at a local machine shop south of Denver. They have asked that I take a look at their work Monday before they make the final silver soudering. Their number is: 303 791 7550 and I'm dealing with Mike, the shop foreman. Jim

Delong and Hot Pockets,
I had the seal installed about ten years ago and I'm sorry but I don't remember how the seal was attached to the cover. I can't even remember exactly where I had it done. I know it was a little back-alley machine shop in Tucson, Arizona. Silver solder sounds like a good way to go. Leaving the cover bolts loose untill tne pulley is installed may not gurantee the seal will be centered, but the small amount of play in the cover mounting holes can help.

Chevgene, as I said in my previous post, I had the hub of the pulley (harmonic balancers were not used on a '30) smoothed out to make a proper fit to the seal.

Actually, they were. 1930 was the first year for a harmonic balancer. Early in 1930 a crank pulley was used and then later in 1930 the harmonic balancer was introduced and it replaced the crank pulley.