Gasket sealer on transmission pan?

[Katfish]

I'm replacing my transmission pan, it's all beat up from getting hit by speed bumps too many times. 

On the new pan, should I use a sealer on the gasket?  If so what kind?

Thanks

[71fish]

Great question. My trans pan leaks too. I replaced 3 times.. so obviously I'm doing something wrong. Step by step sped instructions would be helpful. cork gaskets are out, so which do you use. I bought the rigid gasket w/ the rubber lining.. is this one good?? If so, do I use clear silicone also??

71fish

[Wrencher]

Auto trans gaskets should be installed with NO sealer.  Years ago, the big 3 experimented with using sealer instead of a gasket.  Works well IF everything and I mean everything is spotlessly clean with no oily residue.  So silicone was okay to use when the trans was manufactured but wouldn't work once the trans was serviced in the field.  Silicone would not stick to oily parts and would break off/fall into pan and get sucked into filter.

The pan flange needs to be flat and true.  Replace pan if necessary.  Install gasket DRY (no glue or sealer).  Use good gasket (dealer's or trans shop - not the cheapie ones folded in filter boxes) and don't overtighten.  And don't use silicone.

[71fish]

Thanks much!!    :thumbs: :thumbs: :guitar:

71fish

[budrinker]

i went through this for months changed the pan 20 times because of a leak well it tured out it was the shifter shaft that was leaking and not the pan at all

[71fish]

Buddrinker - pls elaborate..    How does the shifter shaft leak.. & what needs to be done??

[Rev-It-Up]

After our start-up a few weeks ago, we had some leaks and one of them was the trans. We changed the gasket and refilled.....still leaking.  Noticed that it was leaking out of the same spot...hmmmm.   It turned out it was the dipstick...had a bad o-ring on it. 

[71fish]

Rev - I was thinking that one too, but now I'll def replace. Also going to buy a chrome pan, becasue at least I know it is perfectly FLAT..w/ a drain plug.    :ack:

71fish

[Robb]

IF the chrome pan with a drain plug has a 1/8" nylon gasket....   watch out.
Even though I was careful about not overtightening it...

after a year, mine cracked and started dripping profusely.     

I had that, a warped original pan and a leak around the Throttle kick down after doing a shift kit install.       

[70RTdroptop]

Hey, 71fish - I had the same problem that you have, a leak where the shifter linkage goes into the transmission. There's a pressed-in gasket there that, if not installed perfectly, will not seal correctly and you'll get that tremendously annoying leak.You need to replace that gasket, but very carefully, or you'll end up with another leak. Hope this helps!

[budrinker]

a good test for a shifter seal leak is to wipe down the pan clean and dry let it sit over nite and check for leaks if you have fluid showing its the pan if not start it up drive it park it then check it for leakage if it leaks after the test drive it is most likely the ****er shaft seal

[71fish]

does antone know where I can but a 1 pc rubber / steel reinforced gasket for the 727 trans? I was told you can buy them  :dontknow:

It would be similar to the steel reinforce valve cover gaskets.. which are the best btw   :thumbs:

-71fish

[Katfish]

I got a FelPro from Advanced Auto, it's not steel reinforced, but it is rubber NOT cork.

Advanced #5785235   / FelPro #T0S18583   $6 including tax