727 trans pan gasket that doesn't leak??

Have to have a transmission oil pan that has completely FLAT sealing areas FIRST. Then a non-cork or non-rubberized cork gasket material. I suspect the above part number is for a "reusable" gasket which is rubber-based and soft with bushings in the bolt holes to prevent over-compression of the gasket.

From my own experiences, the only way to get a rubberized cork or pure cork gasket to NOT leak is to put a skin-coat of black high-heat sealer on all side of it. The addition of the sealer seals the cork from contact with any oils it's sealing against. With time, the lighter parts of the oil will wick into the cork and eventually cause a seep, which can grow with time. No amount of additional tightness (which usually warped the sealing surface) would stop the oil migration once it started.

I just put the sealer on the gasket, smear it with a protected finger, on sides and edges, thinly, let it cure overnight, then install. No leaks have happened in the 40+ years I've geen doing this on my own cars. Makes clean-up, should disassembly be needed, much quicker and easier. I've used it on every gasket I install, including carb base insulator gaskets. Works great.

Enjoy!
CBODY67
 

mopar (02464324AD)​


(Someone please correct me if I'm wrong.)
^This^

Best trans gasket period. And it's even reusable. No sealer needed.

1709473898136.png
 
Have to have a transmission oil pan that has completely FLAT sealing areas FIRST. Then a non-cork or non-rubberized cork gasket material. I suspect the above part number is for a "reusable" gasket which is rubber-based and soft with bushings in the bolt holes to prevent over-compression of the gasket.

From my own experiences, the only way to get a rubberized cork or pure cork gasket to NOT leak is to put a skin-coat of black high-heat sealer on all side of it. The addition of the sealer seals the cork from contact with any oils it's sealing against. With time, the lighter parts of the oil will wick into the cork and eventually cause a seep, which can grow with time. No amount of additional tightness (which usually warped the sealing surface) would stop the oil migration once it started.

I just put the sealer on the gasket, smear it with a protected finger, on sides and edges, thinly, let it cure overnight, then install. No leaks have happened in the 40+ years I've geen doing this on my own cars. Makes clean-up, should disassembly be needed, much quicker and easier. I've used it on every gasket I install, including carb base insulator gaskets. Works great.

Enjoy!
CBODY67
I agree.......This is my method almost to a tee. I put a thin coat of the black sealer on both sides of the cork gasket. Make sure the pan is flat and straight and no oil residue on either surface. I then install the pan and bolts. I snug the bolts enough to make contact and leave it over night to dry. The next day, I torque the bolts to specs. I have not used any thread locker nor had any leaks from any gaskets I have done this way. I wouldn't use this method on a reusable gasket but the only reusable gaskets I can remember installing is on my newer Hemi engines.
 
The gasket usually isn't cause of the leak it's the pan. Flat pan, no sealer.

And there are several leak points just above then folks think it's the pan.
 
^This^

Best trans gasket period. And it's even reusable. No sealer needed.

View attachment 647495
I tried one of these, years ago, on my ‘68 Road Runner and it leaked horribly! The little sealing lines didn’t line up well with the recesses on the trans flange, so it didn’t seal at all. I don’t see how you guys get this to seal on a 727 but kudos to those who do!
 
I tried one of these, years ago, on my ‘68 Road Runner and it leaked horribly! The little sealing lines didn’t line up well with the recesses on the trans flange, so it didn’t seal at all. I don’t see how you guys get this to seal on a 727 but kudos to those who do!
That's funny, I had zero problems and you are the first person that I've heard say it didn't work.

A friend that was building 727 transmissions swore by them and he is one of those guys that hates leaks, no matter how small.
 
YES they are available for a 904.
And yes the a500/42rh/re and 44rh/re were available in more than just v6 and non magnum 318s. They were in many 318 magnum equipped vehicles. And every one of those transmissions had the same kind of pan gasket.

That said I've seen a few transmissions lately where you'd be "sure" it was the pan but wound up being the shift shaft seal. Could also be the dipstick tube o ring, front pump seal, front pump outer o ring, speedo adapter o ring. And all will seep down around the pan. Especially the shift shaft seal and the dipstick tube o ring
 
It's not a secret I just don't know it off the top of my head.
I think it's listed in one of my ATSG trans overhaul books, I do have an a500 sitting here that I have to go thru and get a pan gasket for anyway I'll look when I get home.
I can't tell you how many idiots I've seen where the they throw those away and use the cork gasket that comes with a filter and then they think they just gotta empty a whole tube of rtv on both sides in addition. I don't like using ANY rtv on a trans.
 
Have to have a transmission oil pan that has completely FLAT sealing areas FIRST. Then a non-cork or non-rubberized cork gasket material. I suspect the above part number is for a "reusable" gasket which is rubber-based and soft with bushings in the bolt holes to prevent over-compression of the gasket.

From my own experiences, the only way to get a rubberized cork or pure cork gasket to NOT leak is to put a skin-coat of black high-heat sealer on all side of it. The addition of the sealer seals the cork from contact with any oils it's sealing against. With time, the lighter parts of the oil will wick into the cork and eventually cause a seep, which can grow with time. No amount of additional tightness (which usually warped the sealing surface) would stop the oil migration once it started.

I just put the sealer on the gasket, smear it with a protected finger, on sides and edges, thinly, let it cure overnight, then install. No leaks have happened in the 40+ years I've geen doing this on my own cars. Makes clean-up, should disassembly be needed, much quicker and easier. I've used it on every gasket I install, including carb base insulator gaskets. Works great.

Enjoy!
CBODY67
Which black high-heat sealer do you use?
 
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