Moparts

727 Trans sealent?

Posted By: Cuda67

727 Trans sealent? - 07/23/09 02:39 PM

Thanks for any help. I have 2 stamped oil pans. Both leak no matter what I do. Tried the rubber gasket and the good one that Mancini sells. Tried a few sealents and the trans fluid eventually attacks it after a day or so, and the leak is back. I suspected the filler tube, but one pan leaks only in the back. What can I use to fix this *(&*^%) leak.
Thanks
Posted By: stumpy

Re: 727 Trans sealent? - 07/23/09 02:40 PM

Have you checked the pans to be sure they are flat and are you overtightening them. Did you try the MOPAR gasket that has three layers and the can't be over torqued? It had metal reinforcement at the bolt holes.
Posted By: Cuda67

Re: 727 Trans sealent? - 07/23/09 02:48 PM

Thanks.
I'm sure neither pan is flat, or they would not leak. I have no good way of checking. So I'm hopeing to find something to seal them.
Posted By: MadMax58

Re: 727 Trans sealent? - 07/23/09 03:13 PM

Quote:

one pan leaks only in the back. What can I use to fix this *(&*^%) leak.
Thanks



Lay the pan on a flat surface check for gaps between the pan and the flat surface. If the pan is bent straighten it. Look for leaks from up above where the fluid would run down on the pan. Check the gear selector shaft seal, Fill tube o-ring, cooler lines. There is pin in the back of the transmission under the tail shaft which has a o-ring on it. Mine was leaking real bad from the pin. I pulled the pan, cleaned the area up, put a little rtv on top of the pin and let it dry before filling the trans with atf. No more leak from the pin.
Posted By: Cuda67

Re: 727 Trans sealent? - 07/23/09 03:36 PM

I have replaced the O-ring on the fill tube. It the oil pan that leaks. One leaks in the front near the fill tube. I have checked the tube and that is not it. The other pan leaks in in the middle of the back of the pan. So it is 2 diffent spots depending on which pan I install.
Posted By: 74Scamp

Re: 727 Trans sealent? - 07/23/09 04:39 PM

You could hold the pan onto a glass window to check whether it's flat.
Posted By: CYACOP

Re: 727 Trans sealent? - 07/23/09 05:22 PM

Probably leaking from somewhere else other than the pan. DAMHIK
Posted By: SALEM1912

Re: 727 Trans sealent? - 07/23/09 05:27 PM

You could try the form gasket from mopar thats all we use now. BTW they are reuseable.
Posted By: Neil

Re: 727 Trans sealent? - 07/23/09 05:30 PM

Straighten the pan or buy a new one.
Posted By: Anonymous

Re: 727 Trans sealent? - 07/23/09 05:38 PM

As a last resort, check the seal where the shift levers come though the case and go to the valvebody. Sometimes they leak there as well.

Permatex ultra-blue works well to seal but will be a #*$& to get off if you ever want to do maintenance.

Always make sure and re-torque the pan bolts after the transmission has cycled a few times as they will loosen up.
Posted By: scratchnfotraction

Re: 727 Trans sealent? - 07/23/09 07:36 PM

what you looking for is all the above...AND the MOPAR black ATF RTV sealant from the dealer

its the trick to the tranny fluid not eating it,also opt for the new o-ring pan gasket from the dealer for about 12-15$$

take a wood handle and lay the pan on the edge of something solid tap the holes back down and straighten the pan rail from the tranny side

use a 1/4" drive to torque the bolts and dont over tightin them..thats why the pans all bent up

but around the bolt holes is first spot to straight out,IMO

also check the speedo gear plug

I clean the whole tranz with brake clean and air dry...throw a hand full of baby powder up around the gear select shaft seal and a round the dip tube..just cause you changed the o-ring does not mean its not bent as well...this is a very good spot for the mopar black atf rtv


check all other places it can leak first then the pan rail,IMO

Posted By: dOoC

Re: 727 Trans sealent? - 07/23/09 07:50 PM

Wanna' be DONE with pan leaks forever ? ...

Get a cast alum pan and be done-with-it.
Posted By: dusturbd340W5

Re: 727 Trans sealent? - 07/23/09 10:12 PM

get a good pan use the mopar gasket that is reusable and forget about all the RTV and sealers they have there place and on a trans is not one of them
Posted By: Cuda67

Re: 727 Trans sealent? - 07/23/09 11:37 PM

First, thanks to everyone. I gave up and ordered a cast aluminum pan from Summit.
Posted By: stumpy

Re: 727 Trans sealent? - 07/23/09 11:38 PM

Now all you need is the GOOD gasket from Mopar.
Posted By: 69L78Nova

Re: 727 Trans sealent? - 07/24/09 12:42 AM

Ive only had luck with a cork gasket. Never had one so much as seep
Posted By: stumpy

Re: 727 Trans sealent? - 07/24/09 01:16 AM

Quote:

Ive only had luck with a cork gasket. Never had one so much as seep


Have you tried the new mopar gasket? The way it's made makes it just about fool proof and it's reusable.
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