The Stovebolt Site Forums The Shop Area Engine Shop Cam Gears '59 235

I seem to have an oil leak from behind my timing gear cover. It's not the oil pan or the cover itself, I've already been through them, I think I have a leak or a failed gasket between the back timing gear plate and the block? Where the oil passage is for the timing gear lube nozzle?
That's about the only other place it can be.
So I understand the gears are plastic, what are the chances of getting them off in one piece? Any help is appreciated...

Only the cam gear is fiber originally, and only on car engines. Trucks used a aluminum gear. The best way is to pull the cam, not the gear. You will need to keep the lifters in order while doing this. Not a simple job.

All that to change out the gasket? Seriously?

Where is your leak appearing? Externally there is a small portion of the joint between the plate and the block and also between the plate and the front of the pan. If it is just a leak fed by gravity, you can clean up the joint and apply a small amount of RTV. After hardening for several days you can touch it up with paint.

It only leaks when the engine is running, and it's showing up on the lip directly underneath the timing chain cover. It's definately NOT the cover, harmonic balancer or the front end of the oil pan, I've checked all those areas.

The leak is slow, but over a 45 min period, there is enough oil to cover the frame cross member directly underneath it.

I have been chasing a similar very small leak on my 216. What is a puzzle is that there is nowhere else for a leak to occur, other than the places previously mentioned, unless the front plate or front cover has a hole. Mine uses about half a quart in 3000 miles but even that small amount can make a mess underneath. If you a beak through I would appreciate any new information!

I found that RTV works the best to replace all of the gaskets except head gasket on the 235. All of those cork and paper gasket leaked from the time they left the factory. Properly used, RTV will seal all of your leaks permanently. Works perfect on the front timing plate and cover and main bearing cap. Use it sparingly being careflu not to let sqeeze into any oil passages. Clean and dry all surfaces and wait long enough to set before using engine. Good luck.

I don't see where you mention the front cover seal or the harmonic balancer seal surface. From your description, both of those are suspects. And it sounds like you have a substantial leak! The gasket behind the engine mount/front cover plate can only be replaced after removing the front plate. The screws are staked in place when the engine is assembled, so that operation is seldom done. A part of that gasket seals the front main cap to the front plate, so if that portion is missing, that might be the source of your leak. If that portion of the gasket is missing, you can fabricate a new one out of thin gasket paper, or use RTV as others have suggested. But you have to take off the front main bearing cap (and oil pan) to do that. If you use RTV, take care not to plug the drain holes in the front plate.

Another possibility is that the two cap screws (bolts) that hold the front cover to the front main cap are missing or loose. The bolts pass through the front main cap into a threaded reinforcement on the front cover. You should be able to see the bolt tips at the bottom of the front cover if you take off the harmonic balancer. You might be able to feel with a paper clip, without removing the harmonic balancer, to see if those bolts are in place, but that won't tell you if they are tight.

Hope this helps.

Harvester

With regards to the portion of the gasket between the front cap and the plate, the cork end seal is compressed between the cap, the pan and the plate. The cork seal should seal the plate to the external pan. If that leaks, you can seal it from the outside with RTV.