The LTD's Tranny Leak...

[Heather]

Well, I've missed out on half a season of car shows thanks to this.

We had thought it was leaking from the pan gasket, but have not been able to confirm that.

The gasket leaking just makes no sense to me anyway. It never leaked before. I go on vacation, it sits for two weeks, and I come back to find all the trans fluid on the garage floor. The car sat for years before I picked it up... so why all of the sudden in two weeks would that go bad?

We cleaned up the tranny fluid under the car, and the gasket appears to be in good health. It appears pliable, and not cracked or worn. Looks new, in other words.

I have not yet tried refilling the car with fluid and seeing where it is in fact coming from, as I have been broke and not able to afford to mess with the car lately.

I just have a feeling that something bigger is going on than we all think with this leak.

It may come down to having to sell Handsome if this turns out to be something more major.

Who here would want a mint '79 LTD? (since if it does come down to selling it, there's no way in hell I will get what I want for it on craigslist... and whoever buys it off there will certainly not take care of it the way I have.)

I've kind of been in the market for something a little older anyway. I like the older front end better.

[gadget73]

My car is now leaking from the pan gasket. Its never leaked before, but its been parked for a couple months for bodywork and now there is a lake of fluid under the car. If its wet only around the gasket, replacing it seems like the easiest thing to try. If its wet forward of the gasket, like coming out of the bottom of the bellhouse, it may be a front pump seal. If its from the front passenger side corner of the pan, but up high it might be the O ring on the dipstick tube leaking.

[Lincolnmania]

replace the pan gasket and filter anyway.........like gadget posted, his car has been pissing trans fluid all over my shop......didnt leak out the pan when it got parked for restoration.

and sell the car for a simple c4 rebuild?.........gotta be one of the cheapest transmissions on the planet to rebuild

[1987cp]

and sell the car for a simple c4 rebuild?.........gotta be one of the cheapest transmissions on the planet to rebuild

Quite possibly. The one I've got was $500, and that included the core. I liked it well enough that after getting rid of my '79 I bought it for, I went to the trouble of installing it in my '81 that came with the early AOD. Just drove it today for the first time in probably 2.5 years, still works good.

I have a spare C4 core, but I don't currently know where all of it is!

Thankfully, installing a transmission isn't as hard as people would have you think, so there's an extra $200-plus in your pocket.

[Heather]

I totally don't have $500 for a transmission though.

[1987cp]

Well, on the plus side, cancelling your liability insurance and letting it sit in the garage until you do have the $500 is completely free.

[gadget73]

If its just leaking, it most likely does not need a rebuild. Seals and gaskets are pretty cheap.

[1987cp]

That too. Fel-Pro pan gasket is like $7.50 at your local AutoZone.

One thing I'm less sure of, how easy is it to change the front seal if that's let go? I know the tailshaft seal isn't that bad, though I think you may have to take the tailhousing to a transmission shop to change that out. Place I ended up getting a whole tranny from sold me an extra tailhousing with new bushing and seal for $25.

Me, I tend to have slight issues with the O-ring that goes around the shift lever shaft. Should probably pull that out and change it out, provided I can easily obtain one, but pulling the valvebody to do so is annoying and I haven't the dexterity to do it without yanking the valvebody.

[gadget73]

only time I've ever done a pump seal it was with the engine out of the car. You'd either need to drop the trans or pull the engine, trans probably being easier. I've never done it on a C4 specifically, but I'd imagine most transmissions are basically similar in that department. I'd further wager that most likely if the seal is the problem, you'd see most of the leakage with the engine running, not with the car parked. The stuff around the pan or dipstick makes more sense for a parked car leak.


I wouldn't think the valve body needs to come out to pull the dipstick tube, but I also don't claim to know the C4 very well. It doesn't really make sense to design it that way. Typically the dipstick tube is inserted after the trans is in place just so it doesn't get bent to hell during trans install.

[1987cp]

Well, yes, I of course meant how hard is it once the tranny is out, you silly neener head. I agree with your logic about when one would see leakage, though.

I assume her C4 is pan-fill like mine is (also having been for a '79 LTD), which means the dipstick tube comes off first via a really big inverted-flare connection. If you're lucky, it'll come off nicely. If you're really lucky, it'll twist the side of the pan right out instead of unscrewing. (That happened to me, and I spent the next week hunting high and low for my torch so I could at least reuse the dipstick tube!) Thankfully, it looks like if I wanted to, welding or brazing the tube boss back into the pan wouldn't be too awful - and failing that, replacement pans aren't that hard to come by, and TCI and others sell a pan-fill conversion kit in case you end up with a replacement that's not already so configured.

If the pan comes off, cleaning the filter screen is easy also. Just be careful of the corner that has a little spring and a little valve thing hiding above it - I discovered mine by having the spring and valve fall out on to the driveway, but thankfully I still had my old core, so it was easy to make sure I got them back in correctly.

[88grandmarq]

it may or may not be the pan gasket.

C4's have external Band adjusters, the jamb nut has a built in rubber seal on it, after you crush them twice, Ford says to replace it. its possible those are leaking.

dipstick tube also has an o-ring seal around it, which could be leaking. typically a leaking dip stick tube will show up when the car is parked.

me thinks you have a combination of both leaking, if there are large puddle under the car after it sits.

[1987cp]

You missed my post. The dipstick tube on a pan-fill LTD trnas is a big inverted flare connector. No O-ring there.

[88grandmarq]

how do you know its pan filled? I have only seen pan filled units in trucks.

[1987cp]

I'm making a wild assumption because my car was a '79 LTD, and her car is also a '79 LTD. Either way, we won't know for sure unless we see the car in person or Heather posts with more info.

When I went to the transmission shop to order my C4, they acted like large bellhousings and pan-fill configuration were all but ubiquitous and the man concern was whether to use a "11 inch" or "12 inch" converter.