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I’m installing a new cork gasket on the chain case. Does it seal right up or do I need to put some sealant on it first before I tighten it up?

cork gaskets do not need any sort of goo on them.
What most do is tighten them way way way too much and that chops the gasket into peaces.
You only need to fo them up till the bolts snug down the 1/2 to 1 turn so there is a lot of gasket material that can compress when the cases get hot & expand then expand as the cases get cold & contract.

bertsmobile1 said:

cork gaskets do not need any sort of goo on them.
What most do is tighten them way way way too much and that chops the gasket into peaces.
You only need to fo them up till the bolts snug down the 1/2 to 1 turn so there is a lot of gasket material that can compress when the cases get hot & expand then expand as the cases get cold & contract.

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Thank you for reaching out to me on this I appreciate it

I heard you must soak a cork gasket in oil, prior to installing. That way it will start to swell and seal properly. Like mentioned, finger tighten the nuts only.

slomo

slomo said:

I heard you must soak a cork gasket in oil, prior to installing. That way it will start to swell and seal properly. Like mentioned, finger tighten the nuts only.

slomo

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Not true
Cork fuel tap gaskets generally get a soak so they do not crumble.
If the gasket is very old like some of the 80 year old ones I use on motorcycles then, just like paper they can dry out and need a soak to swell up & soften .

I have a few old land rovers among a few other (hobby) cars to keep my life nice and stressed. They use cork gaskets from the factory for the oil pan, which dry up and leak. The latest update is to not use the cork gasket, and use RTV (I use Right Stuff), running a nice bead around the oil pan, let the RTV set for a few minutes, then hand tighten with wrench just until it begins to squeeze out, let it sit over night, then torque it up the next day. Just a thought if you did not want to use cork.....

bertsmobile1 said:

Not true
Cork fuel tap gaskets generally get a soak so they do not crumble.
If the gasket is very old like some of the 80 year old ones I use on motorcycles then, just like paper they can dry out and need a soak to swell up & soften .

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Bertsmobile1, the original topic was on the chain case. There is no fuel anything in the chain case. Maybe you have a Snapper that has a fuel tank, in the chain case?

If you install a cork gasket dry, say a valve cover for another example, there is a chance it would leak. Reason for soaking/coating in oil prior to installation. Just a thin film of oil is all that's required.

slomo

We will have to agree to dissagree on this one.
Never oiled a cork gasket on anything and my motorcycle chaincases don't leak from the gaskets.
When a gasket is very old and has shrunk they do ge t soaked in boiling water for a while, then allowed to dry for a day before installation .
Very thin ones might get hylomar on one side & grease on the other but this is just to allow the gasket to stick on one side & strip clean on the other so they do not break when I remove them

No worries Bert. That 00 Snapper grease is thick enough not to get past the cork. But hey, old gaskets do their thing as we know, leak.

slomo

slomo said:

No worries Bert. That 00 Snapper grease is thick enough not to get past the cork. But hey, old gaskets do their thing as we know, leak.

slomo

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Ha! I can tell you they 9 (cork gaskets) leak like crazy on old land rovers. I'll try soaking sometime, if I ever use one again, that's interesting.

timc1018 said:

Ha! I can tell you they 9 (cork gaskets) leak like crazy on old land rovers. I'll try soaking sometime, if I ever use one again, that's interesting.

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You said old so I bet they gave a good service life before leaking. At least RTV silicone hasn't came up to use OMG. LOL

slomo

not sure what you consider service life but they leak after a year or two. The “Right Stuff” no leakss. I quit using cork gaskets 20 years ago. Been using Right Stuff or Black RTV for the last 20 years in place of cork (on old English cars)

If the surfaces are machined, I use thin paper and/or Loctite 5xx depending on application and machining quality.

I have no experience using anything on lawn mower engines, so I really should not of replied and gone off track....sorry.

timc1018 said:

not sure what you consider service life but they leak after a year or two. The “Right Stuff” no leakss. I quit using cork gaskets 20 years ago. Been using Right Stuff or Black RTV for the last 20 years in place of cork (on old English cars)

If the surfaces are machined, I use thin paper and/or Loctite 5xx depending on application and machining quality.

I have no experience using anything on lawn mower engines, so I really should not of replied and gone off track....sorry.

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Hey, glad to hear another opinion. On mowers, I've learned to stick to OEM say Snapper parts for example. Snapper engineers were/are brilliant and know what type gaskets to use. Can't go wrong with real Snapper stuff.

Now in the automotive world, everyone is using RTV silicone of some flavor. Now they make so many different formulas like rear diff fluid RTV. We didn't know that the high pressure agents in the oil (sulfur) add pack eat regular silicone and leak. Another dislike for me, I don't prefer any quick drying or curing glue or silicone. They never have the strength like JB Weld for example. The slow version has more PSI strength. Any-hoo thanks for the comments Timc1018.
Oh and everyone gunking RTV on every gasket surface causing chunks of RTV getting where it doesn't belong. BTW normal RTV silicone needs oxygen to cure. So machined flanges doused in RTV might not cure and seal. Reason why they make anaerobic sealants.

slomo