drwet

What is the best way to stop oil from leaking out between the vibration damper and the crankshaft? I am just about to install my vibration damper. When I disassembled my last engine it was evident that oil had been leaking between the crankshaft and the damper, and pooled behind the crankshaft pulley. Obviously I can't put a sealant on the crank before I install the damper, but I'm thinking if I smear some silicone around the nose of the crank where it meets the damper before I install the pulley that might help. Anyone have any tricks for this?

DUB

Put in a new oil seal that goes in the timing chain cover. Then verify that the machined surface of your vibration dampener is GOOD and does not have a grove in it.

They do offer a service sleeve that can be pressed onto the shaft of the vibration dampener to make it perfectly smooth again so it can seal.

DUB

drwet

You misunderstand. I'm trying to prevent oil leaking between the crankshaft and the vibration damper. Not at the seal.

lionelhutz

You can put a little sealer onto the crank or inside the damper when you install it. Around the keyway is a good place to put it. Just use a little.

Hammerhead Fred

Supposed to use anti-seize between snout and damper.

drwet

I agree. That or a little oil.

Just thought somebody might have thought this through before me. The damper is a .002" press fit so there probably isn't any leakage there, but I suspect that the oil is getting through the keyway. l think I will smear some silicone where the crank meets the damper before I install the crank pulley. Don't see any other solution.

68blvert

You are correct. Oil is weeping down the keyway. Put a small dab of ultra-grey in the key slot in the damper. Most oem's that still have keyed dampers do it this way.

HeadsU.P.

I don't see how oil can go up hill, but maybe. The way engines sit in their bays they drain towards the rear. Hence the intake manifold carb pad is slightly inclined in the back to match the angle of the engine.

derekderek

Take the bolt-washer off. Put silicone sealer at the space between washer-balancer and washer-bolt. You might stop the leak without having to pull the balancer.

DUB

He already has the vibration dampener off the engine.

DUB

7T1vette

Nearly all silicone sealants are very poor at sealing petroleum products (oil, fuel, etc). Use Permatex Ultra Black RTV silicone for sealing oil & fuel.

stingr69

Surface gets splashed plenty during operation. All you need is small clearance. A little positive crankcase pressure will assist, if any.

HeadsU.P.

Where is the oil going to leak out at? Most of the damper is inside the timing cover. So, would it leak out by the dampers bolt & washer? Never seen a damper leak, never heard of one leaking. Its the chain cover seal. A 0.02 clearance is not enough to allow oil to slip past. All shop manuals state to apply a film of oil on the damper when installng anyway. If it were truely an issue, the manual would state: apply Permatex Black to the crank snout.

DUB

Which is why I responded the way I had previously in my first post.
I have yet to have a harmonic balancer leak out from where the key way is. But...stranger things have happened.

Not that it matters...but I am a fan of this product and I would use it in this area.

https://www.permatex.com/products/ga...ealant-liquid/

DUB

lionelhutz

It's rather silly to claim oil can't be leaking past the keyway or between the crank snout and the hub of the balancer of the original posters engine. The original poster found oil behind the crank pulley so his is leaking.

A Google search for harmonic balancer keyway leaking oil will return lots of results with people finding oil weeping past the keyway.

So, it can be leaking around the keyway. Applying a little RTV around the keyway is the fix.

drwet

Thanks to everyone. I installed the damper last night with a small amount of silicone in the keyway of the damper. Pretty sure that will take care of it, although I won't know until the next time I take the engine apart. Hopefully that will be many years.

68notray

I always put a smear of Ultra Black on both the keyway and the back side of the big damper washer for good measure. Can't hurt, and might just stop the dreaded keyway leak before it starts.

corvetero

Maybe I am wrong, but is not the washer in direct contact with the pulley instead the damper per se?

HeadsU.P.

Can't remember. But I believe the washer diameter is slightly smaller than the hole of the pulley. Thereby making the washer in full contact with the damper. The pulley is bolted on later with three bolts after the damper / crank bolt & washer are torqued.
I believe the washer is about 1 1/2 dia. And the pulley had a 2" dia hole maybe?

Very strange story about a keyway leaking. Up hill mind you. Crank snout is higher than flywheel flange.

corvetero

Maybe we are not talking about the same washer, I was meaning the big one on the center of the pulley.





Is there another one between the pulley and the damper?