AOD Leak

[Tiggie]

I put the '88 offically back on the road two days ago. Ever since, I have been fighting a huge tranny leak. It was not leaking at all when I bought it home six months ago.

Skip to the next lines for the short story--------------------

I changed the fluid and filter a couple weeks ago (didn't drain converter, only pan). I put 4 1/2 quarts back in, bringing barely in the crosshatched area on the the dipstick, cold. I figured that once it warmed up, it'd be good to go.

Well I drive it two days ago. I get it inspected and come back to the house (about 40 minute trip, one way). It's leaking up a storm. I look underneath and it looks really wet neat the lines. So I take out the lines and reseal them. I took it for a short trip and no leaks. Good.

Yesterday I took it to Lynchburg (about 1 hour one way). It was leaking even more. I jacked the car up and ran it, but to no avail. I couldn't tell where the leak was coming from. I check the dipstick and it's up to the "NOT" in "DO NOT ADD..." Overfull! I let the car cool down overnight and checked it this morning cold. It was at the top of the crosshatched markings on the dipstick, cold idling in park.

Nothing to do but suck some out. So I sucked some out of the dipstick tube, took it for a 15-minute spin, and came back. It was leaking still. And it is at the top of the crosshatched, hot idling in park.

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I get underneath again. It is definitly coming from the passenger side, but not the lines. Nothing has came out of the vent cap, ever (and it's not stopped up). It is up higher, at the plug thing highlighted in the attached picture. I can't tell anything about the plug. Can it be tightened or seated some more? Is it even a plug?

[Tiggie]

Well, I just went back outside to the garage. It's leaking from the drivers side as well. From somewhere. There was so much fluid everywhere that I sprayed it with Gunk and rinsed it off. Once the water dries, I'll start it back up and look for more leaks. It has to be coming from somewhere up top. Any suggestions?

On the bright side, the underside of the car is now rustproofed for 5 years...

[Tiggie]

Okay, it was washed and dried. I took it for a short ride around the block. No leaks that I could see. Took it a little farther, and wala, leaks.

I can tell that a tiny amount is coming around the netrual safety switch. But the larger concern is the oil slick on the passenger side. Above the cooler lines, above the little plug thing mentioned earlier.

As far as I can tell, there is nothing up there farther than that. No where for fluid to come out, but yet fluid is coming out. Anyone have a picture of an AOD, looking down on the top? There is no reason for it to have a cracked case, and I would guess it would be doing more than just leaking if that was the case.

The TV pressure is set high on this car, but not super high. Shifts at about 17mph to second, 32 to third, and 50+ for OD. It will not go into OD unless you are 40mph+. With 3.27 gears.

[P72Ford]

I have seen an AOD from the top, but I can't remember if there is anything else above that "plug". I know that a TH400 has a small vent right on the crown of the case. Maybe the AOD has something similar; I don't remember that though.

Also, you should have drained the converter. I'm not here to scold you though, although there is alot of fluid in there.

[Tiggie]

I wanted to drain the converter, but my dad convinced me not to. I told him the fluid was horrible. He said that it would be fine. Then, during all this, he pulled the dipstick and asked me why the fluid was brown. I told him because I didn't drain the converter. But that is the least of my worries.

The only thing I can think of is that it is blowing it out the dipstick tube. However, the dipstick is always well seated and never wet at the top, and there is no fluid on the dipstick tube. There is fluid all over the bellhousing, smog crossover tube, and on the top of the front of the transmission (more so on passenger side than drivers side).

It is not overfull anymore, at least according to the dipstick. But the oil dipstick is way way way off from being correct, could be the same on the trans but I don't think so.

I guess I will drive it some more, and if it keep puking take it to the tranny shop. This car is a money pit.

[Tiggie]

Hmmmm....

[P72Ford]

No vent tube on that picture.

Its funny you should mention it blowing out the dipstick tube. The other night I was following my buddies '67 442 (w/TH400). It started smoking like crazy all of a sudden. I could smell that it was oil burning, and told him to pull over. Sure enough, trans fluid was blowing out the dipstick tube. It was all over the passenger side header (causing smoke), and the firewall. It was quite obvious it was coming out the dispstick tube. You would definitely be able to tell if thats where it was coming from.

A few other thoughts: One time my dad was plowing snow in our F350 (dual rear wheel dump, C6). He got the trans hot, and fluid was barfing out underneath. Not sure where it was originating from, but it was pouring out.

Also, the AOD in my brothers '88 (my old car) tends to spray fluid out at times. It blows on the exhaust, and smoke can be seen coming up from the cowl. At times the rear seal leaks too. I had a feeling the trans was getting hot and barfing so I adjusted the TV pressure, thinking that there wasn't sufficient line pressure, thus causing the trans to slip. There hasn't been a problem since. However, you say the TV is set high on your car already.

I'm not sure man, but I hope you can get it figured out.

[gadget73]

you sure its not just pissing out of the cooler lines? those quick connects are known to fail and leak. I've seen those things hemmorage fluid at alarming rates before, especially if they get touched after many years.

[Tiggie]

It definitly doesn't look like it is the lines, unless one is spraying a fine mist upwards. But the fittings on the lines and the lines themselves are completely dry. Even the case around the lines is dry until the oil slick starts running down from the top.

The trans does get really hot and it doesn't seem to puke until the fluid has a chance to get hot. But it's not sprayed all over the firewall, HVAC box, or exhaust manifold like I would think it would be if it was coming out of the dipstick. It is all over the bellhousing, I just don't know how it could get there.

I have a good tranny guy that is relatively cheap and has a good reputation for finding the source of tranny leaks. I'm gonna call him Monday and set up an appointment.

[Lincolnmania]

those quick connects could be spraying fluid upwards......the plastic and the o rings cant take the heat after 20 yrs

[Tiggie]

It is amazing how new oil and burnt tranny fluid can look identical. That's right, it wasn't tranny fluid. It was oil. And it's coming out from the rear lower intake seal. Or more correctly, blowing out. It came to me as I was again examining behind the engine in the firewall area. I pulled the oil dipstick, and it was almost down to full (full is usually the first "L" in "FULL"). That's down at least a quart. No wonder it acts like it has a huge vacuum leak.

Well, at least it is something I can fix and not a freggin hole in the trans case that I was beginning to suspect. Unfortunatly, my fall break ends tomorrow and I won't have a good chunk of time to work on it for another two weeks.

[Lincolnmania]

doh! the old lower intake seal!........vacuum up all the sludge in the intake valley and please change the oil before startup