Author Topic: Transmission sealant.  (Read 1084 times)

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Offline Roger

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Transmission sealant.
« on: Thursday,September 07, 2017, 01:19:15 PM »
I had removed the bellhousing from the 352 ' box, and, discovering that the gasket was NLA I reassembled with a proprietary gasket maker goo. I didn't use the silicone stuff, maybe undue fear of bits falling off inside.
However, the morning after I'd refilled with gear oil, it was all over the floor. So I'll do it again, but what should I use as a sealant? What have other people used that doesn't leak, please?

Offline BDA

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Re: Transmission sealant.
« Reply #1 on: Thursday,September 07, 2017, 01:31:19 PM »
My advise is to do it again. There are some sealants that are applied on the outside. I've tried two and didn't have much luck with either of them.


I have found that oil hangs up in the gears, shift forks, etc. and it never seems to stop dripping. For sealing the bell housing, hold it vertically with the input shaft up. That way, all the oil drips into the end cover rather than on your sealing surfaces. Dry everything as best as you can on the bell housing and tranny case. I would use an even coat of silicone gasket maker. Permatex makes a gear oil RTV gasket maker you might want to try but I'm not sure it's any better than any of the other silicone sealants.

Offline Certified Lotus

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Re: Transmission sealant.
« Reply #2 on: Thursday,September 07, 2017, 03:31:59 PM »
Sports car world in Texas have the gaskets for a 352 (I know, I just got two from them). Always use a gasket (even if you have to make one which is very easy). Apply gasket sealant to each side of the gasket. Make sure the metal surfaces are clean (I use acetone).

Offline jbcollier

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Re: Transmission sealant.
« Reply #3 on: Thursday,September 07, 2017, 09:48:20 PM »
+1 on getting the correct gasket.  The bell housing gasket is available from a number of suppliers: Banks, Ray, Meca, etc.  When using silicone sealant, the surfaces need to be scrupulously clean.  Any residual oil will prevent a proper seal.

Gear oils are somewhat caustic and attack ordinary silicone sealants.  Permatex makes a silicone sealant for transmissions and differentials.

Apply silicone sealant sparingly.  Otherwise large globs form which can break loose and wander through gumming up the works.

Offline Roger

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Re: Transmission sealant.
« Reply #4 on: Friday,September 08, 2017, 02:27:02 AM »
Interesting. Ray told me they were NLA!

Offline jbcollier

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Re: Transmission sealant.
« Reply #5 on: Friday,September 08, 2017, 05:37:00 AM »
Sorry, he used to list them.  Meca has them as that's where I got mine.

Offline Roger

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Re: Transmission sealant.
« Reply #6 on: Tuesday,September 12, 2017, 03:54:44 AM »
Sports car world in Texas have the gaskets for a 352 (I know, I just got two from them). Always use a gasket (even if you have to make one which is very easy). Apply gasket sealant to each side of the gasket. Make sure the metal surfaces are clean (I use acetone).

Thank you, good tip. New gaskets are on the way, then I'll do it again.