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Discussion Starter · #1 ·
Once I removed the transmission pan I saw it had two gaskets on it making me think that was the reason behind the leak. I changed the gasket and filter and put in a little more than 3 quarts and a day later I saw more leaking. Slow drip. I'm trying to figure out what the issue could be. Did I tighten the bolts too much? What else could it be?
 

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Well, for one the bolts look overtightened with the gasket squished out like that. Two, it looks to me like there are other leaks than the pan. Three, did you put any sealant on the bolt threads on the holes that aren't blind?

I'd take the pressure washer & degreaser to the transmission to get all the crud off, then apply a couple light coats of Spray Foot Powder and run it for a day or two to see where the telltale tracks lead from.
 

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When I had a c4 it leaked no matter what I did even with a new steel pan until I got tired of it and just bought a cast aluminum pan. Best thing I ever did.
 

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I used a regular gasket from auto zone and put a dab of the right stuff on each side. Clean all surfaces with brake parts cleaner and make sure no burrs on aluminum case or trans pan. Flatten pan surfaces around holes if needed. Tight is tight enough. Don't kill the bolts. Let dry overnight and add fluid the next day.
 

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The fact it had two gaskets tells me the PO was fighting a leak too. Could be a bent pan, scratched sealing surface or it could be leaking from the shifter shaft if the O-rings is bad. Can’t tell from your pics where it is leaking. Recommend following Woodchuck’s advice and positively identifying the source of the leaks before proceeding.
 
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Thanks I'll look into this. Do you remember the exact pan you got?
It was the deep one by hughes. My car had a 70 or later c4 so I used the supplied filter. If yours is earlier, use the stock filter. Since the flange is 3/8 aluminum you can tighten without fear of warping it. Nice having a plug as well. Never had a pan leak again.

https://www.summitracing.com/parts/hup-hp5180
 

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C4's are a pain. The steel pan has to be razor flat. The gasket has to be a good one and you
can't overtighten the bolts....
We used to drain and get them perfectly clean. Then we'd literally "glue" the pan on with
Ford Trim & Weatherstrip adhesive. (which you can't get anymore) If you allowed it to skin
just right, and then assemble, it wouldn't leak.
 

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I used an aluminum pan and a Lubelocker gasket from Summit Racing and have had no problems. After reading the gazillion threads about leaks and with the price of ATF, I feel it was worth it.

I also rebuilt my entire transmission this winter using the Badshoe productions videos (about $35) In the video he shows you everywhere you could have a leak from and you fix them all in the rebuild. He even sold me a rebuild kit and customized it to exactly what i needed for rebuild. Great guy, responds to emails quick as well.
 

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Aluminium pan here too. I wanted it for the deeper sump because of the nature of my transmission(bigger stall, fluid runs hotter even with a stacked plate external cooler). It did also fix the pan leaks. It also has a magnetic drain plug which is nice when you go to pull the pan off for any reason.
 
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The main problem with metal pans is that even if you tightened it correctly, it may have been overtightened many times before. This distorts the bolt holes to the point where the gasket sealing surface is wavy and basically will never seal. Usually some work with a small ball peen or body hammer and a flat file will put one right. A good quality gasket certainly helps. I really don't like those black rubber ones which seem to be all the parts stores carry these days. They ALWAYS "squish out" when installed. My personal preference is a fiber (paper) type gasket but you'd have to order one from somewhere most likely. Second choice is cork. I don't like to use cork in any shape or fashion on my cars but it is a bit more forgiving of less than perfect surfaces than fiber.
I don't use any extra sealer on gaskets. It rarely works well in the long run and I regard the use of sealer as a poor substitute for quality workmanship.
That was a member here who ended up having the gasket surface of his case machined flat out of desperation to stop the leaks. (It worked) If you are trying to deal with parts in a condition THAT bad then alternative approaches are certainly excusable. People have noted that Chrysler sends some transmissions out of the factory with no pan gaskets. Instead they use an RTV which suspiciously resembles "The Right Stuff". It works for them. The problem with us doing that is that both sealing surfaces HAVE to be perfectly clean and dry or it will NOT seal. If you've ever changed a transmission filter you've probably observed that fluid will keep dripping and oozing for hours if not days. Kind of hard to achieve a perfectly dry gasket surface with that going on. Which is why there exist gaskets for those particular Chrysler transmissions (41TE's), nobody's got time for all that cleaning and drying. Fiber and cork gaskets are quite tolerant of fluid being in the way.

One big thing to remember is that fluid runs downhill. Fluid from anywhere else will ALWAYS look like the pan is leaking. Fluid's drip path can often be spotted by a "clean" surface. The transmission is being washed clean by the leak while the area nearby will be greasy black. Sometimes you have to touch the clean appearing area to see if it is in fact clean and dry or if it is fooling you and oily wet. The picture of your shifter shaft area above should now look very suspicious to you.
 
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