Finals Gasket Sealant

JimInOz · Dec 27, 2015

I've been wondering if there is a certain Gasket Sealant that should be used when re-fitting a Final Drive Housing on an older Komatsu dozer?
I want to do it once only!What experiences have you guys had?

Thanks
Jim

NCWayne · Dec 27, 2015

I'm sure Komatsu has their own, recommened sealant, but any quality sealant should be just fine. By quality sealant I'm talking about something like Ultra-Gray, or the orange sealant that CAT makes. I'm sure there are others, but all will do the job just fine. In fact many of these type sealants are being used in place of gaskets now days, where gaskets used to be routinely used.

Regular silicone can be used, but if you use it, do so sparingly. The big mistake made by many is to put on a heavy coat of the stuff. Once the parts are together it squishes out to the inside and leaves pieces that are prone to breaking lose and clogging oil holes, getting inside bearings, etc, etc. Yes, the Ultra-Gray is silicone based, but it's far less likely to cause problems than regular silicone because of the way it's made.

JimInOz · Dec 27, 2015

Thanks NCWayne,
I think I've seen Ultra Gray somewhere.I had heard that a few of the sealants used in the past were no longer available.(ie Red Hermetite?)
The Komatsu manual makes no recommendations...I think they assume only Komatsu mechanics will use their books.
I have a new gasket ready to go,but just want the best outcome I can get.

NCWayne · Dec 28, 2015

If there is a gasket in the joint, then it should seal with just the gasket, without needing anything else. In fact some gaskets have an additive in their mix that helps them seal once compressed, so you don't want to use anything else on them or it could compromise the seal.

That being said, depending on the design of the joint, the gasket material used, etc I'll often use either a spray on gasket cement, or a really thin layer of Ultra-Blue. I don't use it so much to help seal the joint as I do to help keep the gasket in place as the parts are assembled.

dpendzic · Dec 29, 2015

i have always used a non Hardining type of permatex---either form a gasket or aviation grade

JimInOz · Dec 30, 2015

Yes,I use the non-hardening Permatex too.I like the application brush.

I spoke to a Komatsu dealer...no luck.The guy didn't really have a clue.
As I suspected,If it's older than 5 years,it don't exist!

I'll just go with a light coat of Ultra Blue or Gray.

Ian Beale · Dec 30, 2015

Jim

Story around here is that if your Komatsu is older than 5 years they don't restock parts as sold. But parts are available - hot off the lathe in Japan if you're patient.

JimInOz · Dec 31, 2015

I think all the manufacturers have tightened up in the Spare Parts area.
I got my housing gasket by special order from Japan.Price was OK,as they put it in with a bigger order.
I was annoyed that they couldn't tell me a few minor tech details.I guess that's why we need forums such as this..

The build quality on my old Komatsu is great..thick cast & steel everywhere.
A guy I know told me a story of a new $26K Chinese crawler Loader that had BENT the boom arms.He had the audacity to try & load a log onto his truck with his new toy.Insurance Co wrote it off. I told him to go buy a 30 YO machine made of real steel.
I've never seen any crawler/wheel loader that had bent it's boom while lifting.Which is why this old gear is worth persisting with..

Jiles · Jan 2, 2016

I do not use gasket sealer unless I consider the surface to not be perfectly flat or eroded.
I think most gasket failure is due to improper torque or un cleaned old gasket.
I like to use sandpaper, when possible, to get a shiny gasket surface.
If I ever use a sealer, I prefer to use Permitex 2 applied with a thin even coat, similar to a coat of paint.

Finals Gasket Sealant

JimInOz

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NCWayne

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JimInOz

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NCWayne

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dpendzic

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JimInOz

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Ian Beale

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JimInOz

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Jiles

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