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Vibration damper oil leak

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Old Feb 12, 2018 | 06:56 PM
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Default Vibration damper oil leak

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?
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Old Feb 12, 2018 | 07:08 PM
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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
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Old Feb 12, 2018 | 07:52 PM
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Originally Posted by 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
You misunderstand. I'm trying to prevent oil leaking between the crankshaft and the vibration damper. Not at the seal.
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Old Feb 12, 2018 | 07:58 PM
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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.

Last edited by lionelhutz; Feb 12, 2018 at 07:59 PM.
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Old Feb 12, 2018 | 08:02 PM
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Originally Posted by 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?
Supposed to use anti-seize between snout and damper.
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Old Feb 12, 2018 | 08:48 PM
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Originally Posted by Hammerhead Fred
Supposed to use anti-seize between snout and damper.
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.
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Old Feb 12, 2018 | 09:47 PM
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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.
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Old Feb 13, 2018 | 11:51 AM
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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.
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Old Feb 13, 2018 | 06:15 PM
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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.
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Old Feb 13, 2018 | 06:24 PM
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Originally Posted by 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.
He already has the vibration dampener off the engine.

DUB
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Old Feb 14, 2018 | 07:40 AM
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Nearly all silicone sealants are very poor at sealing petroleum products (oil, fuel, etc). Use Permatex Ultra Black RTV silicone for sealing oil & fuel.
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Old Feb 14, 2018 | 09:52 AM
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Originally Posted by 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.
Surface gets splashed plenty during operation. All you need is small clearance. A little positive crankcase pressure will assist, if any.
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Old Feb 14, 2018 | 03:52 PM
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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.

Last edited by HeadsU.P.; Feb 16, 2018 at 10:02 AM.
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Old Feb 14, 2018 | 07:01 PM
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Originally Posted by 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 the damper when installng anyway. If it were truely an issue, the manual would state: apply Permatex Black to the crank snout.
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

Last edited by DUB; Feb 14, 2018 at 07:03 PM.
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Old Feb 14, 2018 | 10:56 PM
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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.

Last edited by lionelhutz; Feb 14, 2018 at 10:58 PM.
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Old Feb 15, 2018 | 08:22 AM
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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.
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Old Feb 15, 2018 | 08:21 PM
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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.
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Old Feb 15, 2018 | 09:26 PM
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Originally Posted by 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.
Maybe I am wrong, but is not the washer in direct contact with the pulley instead the damper per se?
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Old Feb 16, 2018 | 10:22 AM
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Originally Posted by corvetero
Maybe I am wrong, but is not the washer in direct contact with the pulley instead the damper per se?
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.
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Old Feb 16, 2018 | 10:39 AM
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Originally Posted by 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.
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?
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