Not me. Have you tried a single gasket with RTV on both sides?

Edit: I’m just now catching the “C4” part of this thread. I thought we were talking engine oil pans. I can’t provide any guidance on the tranny oil pan other than 2 gaskets does not seem like a good idea. My apologies.

 

Rtv and pan gaskets don't play well together as the rtv will act almost like a lubricant and the gasket will usually push out in no time.

 

Rather than RTV, how about some simple gasket sealing stuff?

 

an old time mechanic told me to use weatherstrip adhesive & glue the gasket to the pan AFTER making damm sure the pan rails are flat and the contact surface on the trans is surgically clean. been doing it that way for 40 years without any leaks. try it.

 

Silicone will slide out of place. You have a new pan which should have a nice flat surface. Make sure the transmission gasket surface is spotless. Use High Tack spray adhesive. Only glue it to the PAN side. Torque bolts to FACTORY specifications in a alternating pattern. I think the spec is 14 ft lbs. You'll need to confirm the spec.
You shouldn't have an issue post.

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Generally speaking, no. One gasket installed correctly works as intended. From my experience, most leaks are created from over tightening thin flanged parts. Always torque to the low side of the range. After a couple heat cycles, torque it again.

 

Single gasket and some Permatex F-A-G (form-a-gasket)

 

F.A.G. Is silicone. You do NOT want to use silicon with ATF. It winds up allowing the gasket to slide out of place.

 

I’ve had very good experience with Lube Locker gaskets, and they’re reusable. Ford C4 Transmission- LLT-F0C4

Rusty

 

I remember gasket sealing being much easier years ago when your choices consisted of a squeeze tube of permatex or a squeeze . tube of permatex .

After the first couple of times you figured out where to add extra

 

What? No one uses Indian Shellac anymore, to glue the gasket in place?

 

I never use any sealer on any transmission pan gasket. Period. Nor do I want to see it done.
If the pan has not been deformed (most have) by overtightening the bolts at some point, the lowest quality parts store rubber or cork gasket should be able to do its job.
One thing people overlook over and over again is that fluid flows downhill. No matter where it's leaking from it will almost always appear to be dripping from the edge of the pan. No matter what goop you stick on the pan, if you have a leaky dipstick tube seal, kickdown or shifter seal, or even the vent spitting fluid you're not going to fix your leak by messing with the pan.
I've never gotten why people want to glue gaskets to pans. I mean, how hard is it to line up gasket bolt holes on something you are lifting straight up, really? Stuff like water pump gaskets and thermostat gaskets that slide down sideways sometimes need a little stickum to help. Sure. Not transmission pans. Gasket on pan. Stick two bolts in opposite corners and lift the pan in place by those two bolts. Start the bolts, they're already under your fingers. The pan isn't going anywhere so you have free hands to do two more bolts in the opposite corners. Do the rest of the bolts. If you managed to bork up the gasket by following that procedure you are having a very bad day.

I've had to unf%$k a lot of glued, gooped, and otherwise screwed up and leaking transmission pans in my time. And then I have had to guarantee the pan wouldn't leak when I was done with it. Kind of a sore spot with me.
Clean, smooth, and straight sealing surfaces. Bolt holes that aren't stripped. The correct bolts. Best gasket that can be sourced. ("Reusable steel"-cored rubber being favorite.) Making sure there's no other leaks. That's my personal recipe for success with transmission pans.

 

I never use any sealer on any transmission pan gasket. Period. Nor do I want to see it done.
If the pan has not been deformed (most have) by overtightening the bolts at some point, the lowest quality parts store rubber or cork gasket should be able to do its job.
One thing people overlook over and over again is that fluid flows downhill. No matter where it's leaking from it will almost always appear to be dripping from the edge of the pan. No matter what goop you stick on the pan, if you have a leaky dipstick tube seal, kickdown or shifter seal, or even the vent spitting fluid you're not going to fix your leak by messing with the pan.
I've never gotten why people want to glue gaskets to pans. I mean, how hard is it to line up gasket bolt holes on something you are lifting straight up, really? Stuff like water pump gaskets and thermostat gaskets that slide down sideways sometimes need a little stickum to help. Sure. Not transmission pans. Gasket on pan. Stick two bolts in opposite corners and lift the pan in place by those two bolts. Start the bolts, they're already under your fingers. The pan isn't going anywhere so you have free hands to do two more bolts in the opposite corners. Do the rest of the bolts. If you managed to bork up the gasket by following that procedure you are having a very bad day.

I've had to unf%$k a lot of glued, gooped, and otherwise screwed up and leaking transmission pans in my time. And then I have had to guarantee the pan wouldn't leak when I was done with it. Kind of a sore spot with me.
Clean, smooth, and straight sealing surfaces. Bolt holes that aren't stripped. The correct bolts. Best gasket that can be sourced. ("Reusable steel"-cored rubber being favorite.) Making sure there's no other leaks. That's my personal recipe for success with transmission pans.

Having worked in a transmission shop, I concur...

 

Permatex does make a sealer specifically for ATF.

 

Thinking about Fel-pro C4 pan gasket, rtv two together, then rtv to the pan. Trying to stop a leak.

I had an aftermarket pan with drain plug, continued to leak.

I just got the Scott Drake pan without drain plug, seems heavier but still thinking about two gaskets.

So you have been educated why not but if you want to try it out to know for sure,put two gaskets on your oil filter and see how well that works out for you.

 

Did it by accident on a v10 ford in a standby generator. Blew most of the oil out before I could kill it so it don't work so good

 

scott drake?
why not find an oem pan. there should be plenty out there for fairly cheap on ebay and scrap yards

 

I feel one of the main points is do not overtighten the bolts. The gasket will deform and squeeze out. I call it medium snug. I have used high tack spray because "the boss wanted it" and it works. I have heard mechanics do not use silicone because you do not want tiny pieces of gasket sealer floating in the tranny fluid.

 

Never, ever, ever, ever, ever, ever use RTV / Silicone / Formagasket /whatevayawannacallit on an auto trans pan unless the goo you're applying is intended specifically to be used with ATF.

Most transmission pan gasket leaks, are not the pan gasket at all, but as others noted: shift shaft seal, kickdown shift o-ring, dipstick tube o-ring, overflow, converter seal or any other number of locations. The fluid follows gravity and airflow.

If your pan is beat up, Scott Drake makes a really nice C4 pan for under $30. Get a rebuilder quality gasket (I prefer Farpak), the correct bolts and clean the case rail to spotless. Ensure everything is flat and true, follow the torque specs in the shop manual and you should have leak-free pan.

 

By all means us a fiber gasket NOT cork. I have a cast aluminum , deep sump pan , no sealer and no leaks .

 

I think they list it as silicone because it has magnesium silicate as one of its primary ingredients.

 

Lube Locker Gasket Expensive but works. Don't over tighten.

 

Don't use two gaskets. That Lube Locker looks to be the best solution. Make sure the pan is not warped or the tranny mounting surface gouged. Make sure none of the holes are stripped, if they are, do a proper repair. Lastly, it needs to be clean.

If you happen to have a vehicle thats uses a 727 tranny, MOPAR (I know this is a Mustang forum, but we are all car guys, and this fits my 77 Scout II with a 727), this is a factory pan gasket they came out with. It's a piece of plastic that basically has a set of double fine "orings" in groove all around the bolts and along the pan rail. You really can't overtighten this unless you are a dummy. once you are compressed to the plastic, it's perfect. No sealer, no muss, no fuss. Wish they would come out with something like this for other trannies (the lubelocker appears close but I have never used one).

Amazon.com: Genuine Chrysler 2464324AC Oil Pan Gasket: Automotive

Prior to this (don't laugh) I used to glue the old cork gaskets to the pan (not the tranny) using Permatex No.2 (yes the gooey browish-black stuff) with a piece of plywood I cutout for this purpose and kept (I've owned my Scout a while). I then would tighten the pan to the specified torque setting (you may need an inch pound wrench). I usually use a nutdriver and that's all the tightness you need.

Permatex No.2 rarely, if ever, has failed me. It's gasoline proof as well. Just don't get silly and put it on the tranny side or head side of valve covers. Silicone leaves a lot to be desired, particularly the old blue or red kind......Some of the newer ones are ok, but our cars weren't designed with these sealants in mind.

No experience in the Mustang, never could find the pan gasket on my Toploader