Leaky FMX pan gasket!!! Ideas?

[jbuening]

Ok, i've tried different ways to install my trans pan gasket and it leaks every time. What are the tricks tips to getting one sealed up correctly? I've tried one with sealant/RTV, one dry, and one with vaseline on the gasket to hold the gasket in place. Any ideas on what i am doing wrong? The only gasket i can find is a standard cork one without the steel inserts, so i'm trying not to overtorque the bolts. I use a nutdriver so i won't overtorque them. I've got another leak and would like your suggestion. I have a leak coming from between the main case and the tailshaft housing. There doesn't seem to be any kind of gasket on there and can't locate one. Should i use gasket maker on it? Kinda worried using gasket maker on auto trans cause i don't want to plug anything up. Other leaks include the dipstick tube and rear seal, but those are easy ones. I think the only place it doesn't leak is the shifter shaft Thank goodness. Let me know your tricks and suggestions!!!

 

[yeloxr7]

Make sure the gasket flange on the pan is flat all the way around. glue the gasket to the pan using Gasgacinch (apply to the gasket and to the pan and let it dry on both before installation). Install tthe pan and snug the bolts with the nut driver. Go around two or three times as the gasket may relax. Don't over-tighten.

The leak in the tailshaft may be due to a bad seal.

 

[jes72mustang]

This must be an issue with FMXs as they get older, I have the same problems with mine around the pan, and the tailshaft. I have to add ATF every few weeks and I keep a large baking shet on the floor uncer the car to try to catch the majority of the drippings. I had it rebuilt last spring and it has been this way since. I am probably going to drop the pan and do a new gasket to get that leak under control then I will work the tailshaft issue later. Any way I am interested to hear other suggestions.

 

[jbuening]

Yeah well i've been through 3 new pan gaskets and every one has leaked, thus the need for this post. Wasn't sure if there was any "secrets" to installing these pans. Yeah i'm constantly adding ATF to it and always leave my "sweat" mark everywhere i park, that in combination with a one-piece oil pan gasket leak you can definitely tell where i have been lately

 

[yeloxr7]

My FMX was rebuilt in 1994 and the only (tiny) leak is at the drain plug I added to the pan.....

 

[ForceFed70]

Are you sure it's the pan gasket that's leaking? Sometimes fluid can flow down the housing and collect around the pan gasket area fooling you into believing it's the pan gasket.

Does it always leak from the same area? That would be a sure clue..

There's nothing special or different about the FMX pan/gasket. If it is the pan gasket leaking, then I would focus on the pan like yellowxr7 mentioned.

FWIW: I always use silicon. Mostly because it acts like a "glue" to hold the gasket in place until you can get everything bolted up.

 

[66bluepony]

Most likely not the pan, probably leaking above and runing down, most likely dipstick tube. With all the trans leaks you said you had, I would be supprised if the pan did not have oil all over it.

 

[bnickel]

i never use rtv on teh trans pan and i don't have any leaks to speak of. it does seep a bit but i think it is actually from the pan bolt holes in the case. they are drilled all the way through. i'll probably dab some rtv in the holes on top of the outside of the case. the only reason you can tell it's even seeping is beacuse the dirt is collecting around the pan rails

 

[jbuening]

I'm pretty sure it is the pan gasket leaking cause there is no fluid on the case above. The dipstick O-ring does leak but there is ATF on the drivers side of the trans at the gasket level. The point about leaking through the bolts is a biggie for this trans. That is where i see most of the leaks coming from. I'll try a bit of silicone or thread sealer on the threads to see if that helps.

 

[jes72mustang]

Like jbuening said, my trans is dry above the pan. I like this thought of the RTV on the bolts in case it is seeping through them. I may give that a try. I am also thinking about doing a new pan and gasket. Does anyone know if new pans are available I haven't checked the usual sourses yet.