97 F150 Mysterious Transmission Leak

***See below for what I found out***

OK. This is what the problem is. Engine was rebuilt in the truck about 1500 miles ago.

Transmission had a leak before, but not as bad. I thought it was coming from the pan or the dipstick, but it is not.

I first replaced just the pan gasket, as it looked to be coming from around the pan. Still leaked.

I have replaced the dipstick tube, o-ring, transmission pan (thought maybe bent pan) and pan gasket. When I first cranked it up and let it idle for about 10 minutes, there were no leaks. I drove to the gas station about 1 mile away. When I got out, I saw the leak was back. It is coming from what looks to be the rear of the transmission pan, maybe just right above it. The rear seal (where driveshaft enters rear of transmission) is dry as a bone. Front of transmission is dry as a bone (except for just a little where it started running towards front of pan after driving the short distance). There is more fluid (good bit) on the rear of the pan and the transmission cross member.

Take the pan off when you can let it sit overnight and drip. Then brake cleaner it and get after it with a blow dryer if you have patience, a propane torch if you don't, just be careful with it and don't burn anything up. If the housing has a crack somewhere you will open it up with the heat. If it is just splash fluid and not pressure you can force good silicone sealant, like ultra gray or something, not the 1.50 blue junk, into the crack. Possible it could be pressure, but I doubt it since it ran for 10 minutes and didn't leak.

As far as oil leaks go, you start at the farthest forward and at the highest point of the leak. If the front of the pan is wet, something is going on with the pan or the gasket. What kind of gasket did you use? Those crappy cork gaskets are worthless. Your best bet is to use a good black RTV or gray RTV for the gasket. Clean both surfaces and just run a continuous 1/16" to 1/4" bead all the way around the pan and bolt it up. Don't smear it or get any tranny fluid on it to the best of your abilities. Let it sit for about an hour or so and you can all but cross off the tranny pan. If you are using a reusable rubber gasket, clean off the pan and the mating surface on the transmission. Slather a bit of ATF on the gasket to lube it and put it on. Clean off any excess and you should be good.

It is a brand new pan and brand new metal lined rubber gasket (both from the Ford dealership).

I took off the old pan and let is drip for a while. Not trying to be rude, but in the many transmission fluid changes I have done, I have never had the need to let it go overnight, and never a leak (I mean, what service dept does that for transmission gasket changes?). I wiped the mating surface on the transmission with 2 separate towels, that way I made sure all traces of fluid were gone. I installed the brand new pan and brand new gasket and torqued it to 120 in lbs. (manual called for 108-132 in lbs., so I went kind of in between).

The leak starts from the rear. I am 100% positive of that. It is coming from the area of the rear of the pan and the crossmember area. It is looking like it could be the gasket that sits between the transmission housing and the output shaft housing at the bottom of that. Not 100% sure, but it looks like that is the problem area. It looks to be a squared off paper gasket from what I could tell.

Probably tomorrow, or the next day, I am also going to jack the front of the truck up to force fluid to the rear of the transmission and see if I can get it to leak and help spot it better.

sounds like a plan, i said overnight to let all the traces of fluid drip out of it so you could see the leak better

if you don't want help don't ask. I understand being frustrated but....

sounds like a plan, i said overnight to let all the traces of fluid drip out of it so you could see the leak better

if you don't want help don't ask. I understand being frustrated but....

I am asking for help. I was just explaining what I had done, just in case it may have changed your idea.

I am asking for help. I was just explaining what I had done, just in case it may have changed your idea.

you may have went to school but can you figure it out on what needs done? like he said if you don't want help don't ask being you went to school. theres alot of people out there that went to school but don't know how to fix it or you wouldn't be asking.

you may have went to school but can you figure it out on what needs done? like he said if you don't want help don't ask being you went to school. theres alot of people out there that went to school but don't know how to fix it or you wouldn't be asking.

WTF are you talking about going to school? I never went to school to be a mechanic. Where are you getting this information from.

You guys are reading too much into this. I asked a uestion. He gave an answer. I told him what I had done, and that I had never needed to let it drip overnight (it is possible, it is just that I have never seen it. I didn't tell him he was wrong). He thought maybe I was questioning his answer, which I wasn't. I just worded my statement wrong. For that, I apologize.

Why are you guys getting defensive?

Again, I apologize if it came off the wrong way. But I would still like to know what made you think I went to school, since you stated it twice in one post.

I don't think you were being rude RBeach. For what thats worth.

Didn't mean to start a drama scene, damn. Youre right though rBeach. I had kids in the classes right along side me that I wouldn't let work on my yard. Schooling doesn't equate to a good mechanic. Do anymore to the truck?

Didn't mean to start a drama scene, damn. Youre right though rBeach. I had kids in the classes right along side me that I wouldn't let work on my yard. Schooling doesn't equate to a good mechanic. Do anymore to the truck?

It's all good. It is hard to read someone's demeanor on a screen! : ) I would still have a beer with you at the end of the day! LOL!!!

It wasn't your post that set me off, it was the other person's that talked about the school thing. Still unsure where they came to the conclusion I went to school to be a mechanic. The only thing I was ASE certified in was brakes and suspension/steering (but that was a LONG time ago) and didn't go to school for it either.

Anyway:

I cleaned the outside of transmission off again and drove it and got under truck again to pinpoint leak. My best guess is the bottom of the extension housing gasket has blown a leak. I ordered one from Ford and should be here today. It was only $15, so figured that would be my next logical step.

I figured I would park it nose down a little to minimize fluid loss when I pull that extension housing off. I figured while I got it off, might as well go ahead and replace bushing and oil seal while I am at it. Cheap insurance against future failure, and having to drop driveshaft again. I might go ahead and replace speedo cable o-ring too. I am going this far, so might as well cross out all possibilities.

So much crap has gone wrong with this truck. I bought it in February. A week or two after I bought it, the engine seized due to a bent connecting rod (if you check your post history, you are the one that actually led me to that, so thanks).

Heck, once I fix this leaking transmission problem on truck, it will be basically a new truck!!! Also, it is throwing a code (not sure which off top of my head), but I am leaning towards a vacuum leak or an exhaust leak. I think it was a code telling me O2 circuit sensor bad or to rich/lean (like I said, not sure of exact code). I will get to that once I get old faithful to stop spewing red blood!!!

On top of that, I have a freaking suspension/steering problem on my Pathfinder. I think karma is paying me back something I did in the past! : )

Sounds like your on track. Let us know what happens. Your welcome for the help on the earlier post, sorry that was the deal though, that sucks that is what it was. You are having a good run of bad luck....

Sounds like your on track. Let us know what happens. Your welcome for the help on the earlier post, sorry that was the deal though, that sucks that is what it was. You are having a good run of bad luck....

You are having a good run of bad luck....

LOL! That's putting it mildly.

We had to drill a new well 2 years ago (went to 327 feet).

This year was a new roof, complete bathroom remodel (stripped down to fllor joists and wall joists and also a new HVAC unit.

Now the truck! I think it is a test of my patience!!!

Going to work on truck tomorrow. I picked the gasket up today. Keeping my fingers crossed.

Problem fixed!!!

It was the extension housing gasket. When I pulled the housing off, the gasket was mangled looking. It looked like someone had replaced it before, and didn't get it on right.

Took me about 2 hours. Would have been shorter, but I kept getting interrupted by a dang ringing phone!!!

Good news on the fix. I know what you mean with the phone, after 10 years my wife still doesn't understand why I get so pissy when she calls me non stop when I'm wrenching on something.....

Glad I found this topic. I bought a 97 F150 in March and it recently sprung a leak. We changed out the pan a couple times and it leaked at the same place every time. We regrouped and I did some research and found this thread. We changed out the gasket on the extension housing and it fixed the leak!

Thanks!