Replacing the transmission pan of my C-4 tranny ('65 Ranchero, 289). The original pan was leaking about the perimeter, probably from DPO over-tightening the bolts. Stupidly replaced it with a chrome increased-capacity pan instead of just peening the stock pan back into shape. Chrome pans notoriously leak and mine's no exception despite having roughened up the gasket surface with a wire brush. But I did like the fact that the chrome one had a drain plug. Can't afford a cast-aluminum pan, but after much searching found a replacement sheet metal pan that isn't chrome and which has a drain plug, although it doesn't have increased capacity. So, with all that irrelevant blathering here's the dumb question: Should there be washers under the bolt-heads? If so, what kind - just flat washers or locking? [And any helpful hints? For example, there seems to be some dispute about what's the best gasket to use, cork v/s synthetic.]
I personally would use shoulder bolts they will have no path for seepage between bolt and washer, as for the gasket I still prefer cork.
I always used yellow monkey snot to attach the gasket to the pan (even chrome ones, that's what babe's engine oil pan is) to remove that surface from allowing seepage; apply to both surfaces as contact cement, wait till both beads dry, then apply the gasket to the pan and press them together. Each bolt gets a flat washer and a little dollop of black spooge in each bolt hole. That's about the best you can hope for with a steel pan, and so far, my C4 hasn't leaked from the pan. That's about a decade and a half since I installed it and the engine. Oh, one more thing: carefully torque the bolts by hand in a cross pattern in order to even out the torque loading, prevent the pan from warping.
Is that how they did it from the factory, I didn't know that, all of the monkey spunk must have melted off of the cars that I worked on. " Gasket sealer is to hold the gasket in place, thus the name gasket". Go simple.
You can ask ANY transmission shop and ALL will say "it goes on without any sealant" Just use a stock cork-type gasket.
I use studs and flange nuts. X2 on the cork gasket. I do put petroleum jelly on it to prevent it from seizing to the transmission case.
Just the stock bolts are fine. Over-tightening is the #1 cause of trans pan leaks. I always lightly tap each hole on the pan, from the top side down, with the round head of a ball peen hammer (with the ball side) before installing, and use a light smear of RTV on each side of the gasket. If you see the RTV squeezing out, you've tightened the bolt too much. I worked in a trans shop one winter, and did 2-3 of these a day with this method.
Thanks for the info, folks! And yet another question: Just received my nifty new drain pan with a drain plug (stupidly installed on the shallow end of the pan, but no big deal because I just need it for when I inevitably over-fill - when changing fluid I'd be removing the pan anyway to access the filter). Appears to be pretty well made, maybe heavier gauge sheet metal than stock. But... It's painted on the inside. I'm thinking that's not such a swell idea, creating potential for contamination of the tranny fluid and that I should remove the paint inside the pan before installing. Opinions?
Yep. It's paint. I had to look around a bit to find a pan that had a drain plug but wasn't chrome: https://www.amazon.com/Assault-Raci...5250&sr=8-1&keywords=ford+c4+transmission+pan It's painted black - inside and out.
Well, decided to error on the side of caution: The paint on the inside of the pan came off pretty easily with paint remover. I figured that if it wouldn't come off with paint remover it wouldn't come off with transmission fluid, so if it didn't work it would be no big deal. And if it did work, well... it'd work. Anyway, I can see no purpose in painting the inside of the pan and can see where it might create a problem so I took it off. Handy andy, I can't seem to find any yellow monkey snot, nor any black spooge. Do those products perhaps also go by other names? [Back in the 70's I followed standard wisdom at that time by using a 3-M product commonly called Yellow Death when putting a VW Bug engine together. Forget what the actual product name was, but I rather suspect it's the same as yellow monkey snot.]
3M Weatherstrip cement. And probably Permatex #2 gasket sealer. #1 dries hard and #2 stays mostly flexible. They're the old standbys before all these new products showed up. I still use them.
This stuff: Many monkeys have given their lives for our automotive needs. Who knew there were so many uses...
Yep, that's the stuff that freaks called "Yellow Death" when rebuilding their Bugs. Good stuff! And, yep, I swear by Permatex as well, and use it as you suggest, as a cheap-rent Loktite. Didn't know the #1 and #2 nomenclature, but I've always used what I now know is #2 for that and for gaskets.
Sorry, I should remember that different people from different places have different names for things. However, I wonder if the name "Yellow Death" came from the idiotic huffers? It certainly has the strength to put you in La-La Land when breathed in.