To Seal Or Not To Seal Gaskets?

I am in the process of an SM420/Dana 18 conversion. I have rebuilt the tranny and now redoing the transfer case. In all my years of putting things together I have never used any type of gasket sealer, glue, adhesive, form a gasket, or whatever with OEM gaskets. With the exception of RTV on intake manifold gaskets at the corners.
I have always had good results. Thread sealant on bolts which protrude into a fluid chamber is necessary in my opinion. Would bolt anti seize do the job of a sealant??? My concern is all the research I have done on the Dana 18 transfer case, everyone seems to seal the gaskets with something. The TC i took apart was sealed with it looks like a thick layer or RTV on both sides of the pan gasket. And still has indications of major seepage. Maybe too much sealant?
Any responses to success will be greatly appreciated, I despise fluid leaks of any kind. Please include information on oil seals, shim sealing and any other leaky annoyance.
Thank you

 

Black RTV....my last Trans/TC rebuild hasn't leaked.....close to 5,000 miles. It doesn't have to be a thick layer, just 100% thorough coverage.

 

Here I go again. I HATE silicon (RTV) with a passion.

Permatex #2 or Aviation Gasket sealer. I sometimes use a little of the red permatex spray gasket sealer.

ARP is a good thread sealant, like for head bolts.

If you think you might re-use the gaskets in future, the old time way was just to use a schmear of grease.

 

Boy, do you have a problem
I'm using Permatex Right Stuff on the D18 I just put together. New seals throughout, speedi sleeves on the yokes.
It's still gonna leak somewhere.

 

If it isn't leaking its low on fluid, I think that's on the third page of the owner's manual.

 

I coated both sides of every gasket with black RTV, but just a smear with my finger and no leaks after my Dana 18 rebuild except from the shim pack at the rear output. No RTV there...

 

Anybody use Permatex spray on shim pack or is it better to put them on dry ?

 

Spray copper

 

In the world of power plants (and my junk at home) there is an art form to sealants. If your flange faces are flat and in good shape, I don't use anything on the gasket. If they are not in such good shape or I have leak issues I go with PeteL.. Permatex #2 aircraft sealant. I only use RTV for metal to metal with no gasket, well, the RTV is my gasket, but that's where the art comes in.. A layer 1/32" thick, set the cover and just finger tight bolts. DO not compress the surfaces.. Let the RTV vulcanize for a few hours, then tighten.. This does two things. It reduces the "squish" into the oil side and chunks of RTV in your machine, and it "forms a gasket" (hence the original form a gasket name" that you are compressing.


You should try sealing Hydrogen in a machine that has several massive flange faces.. You get really good at it haha..

 

Whats the old saying Our Jeeps are just marking our territories.....

 

Yep. Goes right along with lift a leg----

 

Technically, The Gasket is designed to do the sealing. The RTV was used by MFG's instead of gaskets. Like stein says , if it is flat flanged & clean, some Hi- Tack on one surface is all that anyone should need. I agree on the use of Threadlocker, but anti-sieze does the opposite job.

 

I use permatex gasket sealer on pretty much any paper/cork gasket. Have had good luck with that, and it's not goopy like RTV, it's thin and brushes on.

 

x2, this method has worked well for me on axle covers where it had no paper gasket as well.