Tranny pan wouldn't stop leaking.....

Posted By: 440727

Tranny pan wouldn't stop leaking..... - 04/18/10 04:07 PM

I have a big block 727 with a B&M aluminum 4 quart more than stock pan part #10280.

I can't get the pan from stop leaking. It only leaks from the front side of the trans pan aka closest to the bellhousing.

I've done just a rubber gasket no RTV sealer.

Two rubber gaskets with no RTV sealer.

Rubber gasket with a good amount of RTV sealer. And it still leaked.

I then used a rubber gasket with a medium amount of RTV sealer hand tightened the bolts and tightened after an hour. It is still leaking. I made sure the bolts are tight, tightened a little more and its still leaking.

The top of the pan where it meets the bottom of the trans is completely flat. The stock pans have the little ridges on the top of the pans.

Anyone have problems with aftermarket pans not sealing ?

Posted By: stumpy

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 04:13 PM

Why not go to the dealer and get the new style sandwich gasket and install it with no sealant? I have never had one leak and they are reusable a number of times.

Posted By: hydro

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 04:20 PM

Is it the pan leaking or the vent behind the torque converter? If oil is coming out of the vent it will look like the front of the pan is leaking.

Posted By: Dodgem

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 04:50 PM

Another vote for over full and coming out the front vent.
First it says
"727 Deep pan provides an additional 2-4 quart capacity, significantly improving the cooling ability of the fluid."

Usually 2 more is more like it and if you put a higher stall they hold less. when car sits torque drains back and makes it real high and leaks out vent and down front of tranny right to the pan.

Posted By: NachoRT74

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 05:48 PM

linkage seal?

in my experiendce my tranny leaks allways seemed to come from pan gasket, and never were from there... allway linkage seal and rear band pivot seal.

Posted By: Andrewh

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 06:00 PM

I agree. All my "pan" leaks were higher. Feel around or clean it all off and wait for drips. Then touch a paper towel up above the pan.

Posted By: Pacnorthcuda

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 06:29 PM

Yep...at this point its not likely to be the pan.
Maybe the selector shaft seal?

Posted By: BSharp

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 06:30 PM

If it really is a pan gasket leak, make sure one or more bolts aren't bottoming in their holes.

Posted By: HealthServices

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 06:45 PM

Quote:

I agree. All my "pan" leaks were higher. Feel around or clean it all off and wait for drips. Then touch a paper towel up above the pan.

Posted By: NITROUSN

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 06:54 PM

Quote:

Another vote for over full and coming out the front vent.
First it says
"727 Deep pan provides an additional 2-4 quart capacity, significantly improving the cooling ability of the fluid."

Usually 2 more is more like it and if you put a higher stall they hold less. when car sits torque drains back and makes it real high and leaks out vent and down front of tranny right to the pan.

Its impossible to come out the vent when sitting. It would take several gallons to even get it close to the shaft centerline let alone the vent hole.

Leak is most likely dipstick or shift shaft seal,

Posted By: scratchnfotraction

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 09:18 PM

clean and dry with brake clean

throw a hand full of baby powder on the area in ?

the powder will show you the leak way before it spreds to look like it else where

I would deff use one of the new gaskets with the alum pan

Posted By: Dougsmopars

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 09:24 PM

I have a deep chome pan. Used the Mopar rubber gasket and not a drop on the floor. No sealer. There the best gaskets

Posted By: dOoC

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 09:30 PM

x 2 on that baby-powder. But I don't agree at-all with the need to use any trick gaskets on a cast alum pan. Since LOTS of the sealing issues can be traced to bent pan-rails ... using a cast pan eliminates that problem.

Check ALSO the rubber seal for the throttle pressure linkage IN the VB near the shifter-seal in the case.

Posted By: stumpy

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:00 PM

What's so trick about an updated factory gasket that is reusable?

Posted By: dOoC

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:08 PM

....because IMO .. it is not needed. What is the current cost diff ... cork and this one that you refer to ?

Posted By: stumpy

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:12 PM

$0 because you get to use it over and over again instead of the one time cheap gaskets that do have a tendency to leak. That and you can't overtorque it.

Posted By: dOoC

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:15 PM

I have a cork one on my 62 since the late 70's ... R&Red the pan many times .. no leaks.

Again ... WHAT is the cost diff ?

Posted By: scratchnfotraction

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:17 PM

does not matter on the cost..we are high tech with it,and keeping up with the trendy stuff

Posted By: Dougsmopars

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:18 PM

We now have disc brakes. Because there better. Things do improve with time. The new factory pan gasket is 100 times better then the cheap cork they used 40 years ago. Tell me do you still use a rotory phone?

Posted By: stumpy

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:23 PM

Quote:

I have a cork one on my 62 since the late 70's ... R&Red the pan many times .. no leaks.

Again ... WHAT is the cost diff ?

Doc, I really don't believe that. I"ve been in this businness over 40 years and know better. Unless you are using a lot of rtv, which would be doing the gaskets job, that gasket would be too dried out and thin to hold any fluid back.

Posted By: dOoC

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:27 PM

You believe what you want .... I RTVed the gasket ON TO the pan and then lightly oiled the opposite face.

And I have been doing this LONGER than 40 years !!

Posted By: Dougsmopars

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:28 PM

The cork gaskets barely stop leaks when new. They will never come off and go back on and still seal. No way.

Posted By: dOoC

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:29 PM

Quote:

does not matter on the cost..we are high tech with it,and keeping up with the trendy stuff

TRENDY STUFF ? ... how about a DECENT exh system on that motor pic ?

Posted By: stumpy

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:34 PM

Doc, take your oldtimers medicine and join the modern world. There is no way in hell a cork gasket will last 30 years being used over and over again. You got to come up with a better story than that.

Posted By: dOoC

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:38 PM

Grumpy ....just say what the cost diff is ....and I just MIGHT join that "modern-world"(of expensive gaskets) .

Posted By: BDW

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:42 PM

I paid $22 for the new gasket. Not really sure I needed it. Once it was all said and done, my leaks were coming from multiple other places. I guess it would have saved me replacing the cork style 3 times.

Moral of the story, if you think it's the pan seal, look elsewhere too.

Posted By: stumpy

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:44 PM

About $15 difference for a gasket that will seal over and over again without the need for the expense of a tube of sealer even if the pan isn't perfectly straight.

Posted By: dOoC

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:52 PM

Quote:

Doc, take your oldtimers medicine and join the modern world. There is no way in hell a cork gasket will last 30 years being used over and over again. You got to come up with a better story than that.

You CHANGED this post .....

NO old-timers medicine here. But how about YOU ? ... I hear that you are ready for that rocking chair ...

The MODERN WORLD ? .. then why are you messing-around with the 60's and 70's stuff like you do? And I have not "used that gasket over and over again" like you insinuate. I have maybe pulled the pan 5/8? times over the years.

And AGAIN you avoided my simple question.

To c-guy ....22 beans ? .... I don't know what the current pricing is on cork ... but I could be convinced to use the "modern" stuff.

Posted By: Neil

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 10:53 PM

I sealed a TH350 with a flexible rubber gasket and GE Silicone 1 door and window sealer from Home Depot.

My experience with cork is that oil eventually soaks into it and it weeps out the other side. I cut a leaking low mileage cork VC gasket in half and it was soaked with oil all the way to the middle.

Posted By: BDW

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 11:06 PM

The best thing about the reuseable gasket is you don't need to spend time scraping all that RTV off when you do change it.

I fought with a leaking differential cover, it's a major pain getting all that RTV off both surfaces.

Posted By: Neil

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 11:09 PM

Believe me I wanted to use a mopar style reusable gasket for the th350, but couldn't find any such animal. And, yes silicone is a hassle to remove.

Posted By: BDW

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 11:13 PM

These guys have it, wish I had found the Dana gasket before I changed it 3 times.

http://ratech.stores.yahoo.net/reaxhoga.html

Posted By: scratchnfotraction

Re: Tranny pan wouldn't stop leaking..... - 04/18/10 11:54 PM

OHCH! that hurt Doc

i did put a DECENT exhast on it,IMHO

i droped the rear dump log manny on the passide and use 2 center dumps and no heat flapper on the passide

with 2 nice head pipes mandrell bent 90* turns

cant get more = than that with mannys and is mucho more decent

gots the trendy mini alt and mini starter too

if you would like me to use something else..."all donations accepted"