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hey guys i have a question for you do you guys use a gasket or do you use rtv to seal your differentials? i usually use rtv but i think that it is leaking now in my truck however maybe i didnt allow enough time for it to set up? thanks nick.
 

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Permatex "the Right Stuff".

Fluid ready in about 5 minutes.
 

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Both; gasket with light coat of rtv on each side.
 

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Silicon sealer requires proper surface cleaning with an alcohol based cleaner before application with or without a gasket. Oil is considered a release agent for silicon sealers.

Without a gasket:
Apply a thorough even skim cote to the cover. Allow it to set for 10 - 15 minutes at 70° F. Replace cover but secure cover bolts finger tight allowing sealer to come in full contact with the housing. Allow at least an additional 15 minutes before torquing to final torque. This allows the silicon sealer to form a surface between the components instead of getting squeezed out. This works with Permatex "Blue" or the "Black-Ultra" types which have an average setting time of 20 minutes.
 

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I use RTV and allow it to "skin over" before installing the cover to the diff. I also only use a clean rag to wipe the surfaces after removing the old gasket with an abrasive wheel, no special cleaner. But maybe I have been lucky.
I use the same method on axle flanges too.
 

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Silicone never leaks if you clean it right.

Black RTV and brake clean to do it right. If your a cheap ass a tube of tub and tile caulking and brake clean.

Gaskets leak, silicone doesn't.
 

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Silicone never leaks if you clean it right.

Black RTV and brake clean to do it right. If your a cheap ass a tube of tub and tile caulking and brake clean.

Gaskets leak, silicone doesn't.
Amen on the brake cleaner. I use it in this way to final clean before head gasket installs:

Clean and degasket the way you normally do. Make sure it is as clean as you can get it, then apply brake clean to a clean rag, and wipe off the mating surface on the block. You will be amazed at how much oil or grease residue comes off. Repeat using a clean area of the rag each time untill no more residue comes off. Clean the head this way also.
Bob B.
 

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Another vote on "the right stuff"! Once you use it, its hard to go back to regular ol RTV.....and I like the cheez wizz can ;)
 

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Actually you are all wrong.......sort of

Look at your diff cover . Diff covers that are dead flat are designed for the silicone goop. Diff covers with the little raised rib between each bolt hole were designed for gaskets .
But all the stuff about clean surfaces and cleaner were correct . About the only thing I can add is I have had a tough time with leaking gaskets on pto covers. Liquid teflon tape on the screw threads stopped the leaks every time I have resorted to this technique.
 

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Not really. There are plenty of flat covers that originally came with gaskets.

The simple fact is gasket or not when it was new doesn't matter in the least. The only time I use gaskets is when the gasket is important for proper clearance or when the mating surface is completely above the fluid level and designed to be removed easily.

If I use a paper gasket I don't use silicone on it. This is pointless. Silicone just makes a mess out of it if you ever need to take it apart and makes it look like crap. I smear a thin coat of lubriplate over gaskets like this, torque whatever it is properly and it'll never leak. When you take it apart in 30 years the gasket will come right off in one piece too.

If you have to use a gasket below a fluid level gasgacinch works far, far better than silicone does. It's amazing stuff and that's what it's intended for.

If your PTO covers leak it's because you didn't clean it properly or apply silicone evenly. A 1/16" bead is all that's necessary and a tiny dap on each bolt thread if the bolt holes are through tapped like msot PTO ports are.
 
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