Cause Of Tranny Leak???

[1992 Eddie Bauer]

I have a 94 Explorer that I just put a used tranny in. I have been driving it around town a little bit for the past couple months or so and everything has been fine. Shifts real good, no problems....until tonight.

I was driving across town getting ready to jump on the highway and came to a stoplight. Upon attempting to take off the vehicle didn't want to move and the engine revved a little (not bad, maybe 2000 rpm) and then slowly started to move. Once we got across the intersection I looked in the rear view mirror and saw a little bit of smoke. I immediately turned around and headed for home. Came to another stop on the way home and when trying to take off the engine revved to 4000 rpm before it started to move (it was acting like it was either low on fluid or it was slipping, but since I saw smoke earlier, I assumed it was getting low on fluid since it seemed to be draining as I was driving; hence the smoke). Just not sure where it's leaking from.

So I got it home and jumped out and looked under the vehicle to see if I could locate where the leak was coming from (engine was still running) and couldn't see any leaks. I then shut it off and looked under it again and that's when I saw it starting to pour out the vent/overflow tube, which runs on top of the tranny at the rear up towards the top of the bell housing and then down the drivers side of the bell housing. So I watched it pour out probably about a 1/2 to 1 quart of fluid (guessing the amount) before it stopped draining.

It has a new radiator and the lines aren't plugged. Prior to installing it I installed a new filter and pan gasket along with a new front pump seal. So I know there shouldn't be any leaks from those two areas since it has new a new gasket & seal.

Question.....what would be causing it to drain out the vent/overflow tube? Any other possible problems I'm overlooking? I appreciate any feedback.

 

[Centaurious]

Purging out the vent hole was probably from overheating. The question would be why? Low on ATF?

I would hope that your used transmission had a warranty and you can get an exchange.

 

[1992 Eddie Bauer]

Purging out the vent hole was probably from overheating. The question would be why? Low on ATF?

I would hope that your used transmission had a warranty and you can get an exchange.

That was my first thought too; overheating. But I have no idea what would cause it to overheat.

Actually it was about 1/2 too full after getting it installed and filling it up with fluid. So if it became too low, that means it's been leaking slowly (maybe from overheating???). But I haven't noticed any fluid whatsoever leaking from the tranny until yesterday. I'm stumped and not sure what to do.

Because I didn't have $3000+ to rebuild the tranny that was in it, I chose to find one on e-bay that I could afford. I found this one and it had a 3 month warranty, but that 3 months has since passed, so I'm stuck with the tranny and trying to figure out the issue.

Anyone have any idea on what causes a tranny to overheat that isn't low on fluid to start with?

I've done a lot of upgrades and improvements to this vehicle (over $2900 in parts/maintenance & upgrades) and I wanted to get it functioning dependably so I could sell it (have too many vehicles and not enough space), but now that it's having this tranny issue I don't want to sell it until I can figure out what the problem is and how to fix it. I don't want to screw someone over or be dishonest when I sell it and I don't want to sell it to someone knowing they will have problems with it, especially if they won't be able to drive it home without the tranny giving them problems.

 

[Centaurious]

It might be worth it to blow out the cooler and lines. You didn't say what happened to your original transmission but most won't warranty without a cooler flush.

What is the fluid level now that it has cooled and just after starting the truck? It may have purged the extra fluid from the install but you need to check.

 

[trashtruck]

I'll leave this to the trans experts but I assume it's a standard trans and not auto, correct?

 

[Centaurious]

He talked about a new radiator and the lines not being plugged. That and the vent made me think Automatic. Both take ATF but a manual doesn't have a vent line if I remember correctly.

 

[1992 Eddie Bauer]

It might be worth it to blow out the cooler and lines. You didn't say what happened to your original transmission but most won't warranty without a cooler flush.

What is the fluid level now that it has cooled and just after starting the truck? It may have purged the extra fluid from the install but you need to check.

It's an A4LD auto tranny. The old tranny had a lot of miles on it and it was slipping and shuddering so I opted to replace it with a used one.

I checked the fluid level last night after it cooled down and it showed tranny fluid on the dip stick, but this was without the engine running and the truck is parked on a steep incline in my driveway. I was a little nervous to fire up the vehicle to check the fluid until I figure out what's wrong and what to do next.

I've been reading up on this problem since I first posted this and with the train of thought in mind of overheating being the problem, I noticed two common things people mentioned as a possible cause: 1) Wrong fluid or fluid level too low, and 2) a bad solenoid. My fluid level was not too low; in fact it was too full.

With that said, I was told by a transmission shop that Dexron III or Mercon would work in my tranny. Therefore I purchased 9 quarts of Walmart SuperTech ATF and the label states "For use in vehicles previously serviceable by Dexron III or Mercon" Upon installation I only used 8 quarts and it still ended up being too much fluid.

However, from what I've gathered from reading the forums, most people are saying to stay away from "universal ATF" and to use vehicle specific ATF as recommended by the manufacturer. However, I don't know exactly what ATF my Explorer calls for. I assume any Motorsport ATF???? A lot of people have stated that I should use Mercon V. Some are also saying I should use "Lubegard Platinum Universal ATF Protectant" or "Lubegard Highly Friction Modified ATF Supplement" with the "universal" ATF. I also read a Ford TSB that states not to add any additive or modifier. So I'm confused and don't know what to do...

Bottom line....could the fluid I bought from Walmart not be the correct fluid (even though it's Dexron III or Mercon fluid) and could be causing the overheating issue (or whatever issue it is that I'm having....overflowing from the vent tube)????

Regarding the bad solenoid issue.....first of all I'm not sure where this "solenoid" they're talking about is located. There is a round canister looking thing mounted on the outside of the tranny on the passenger side next to the 2 tranny lines and it has 1 hose going to it (vacuum hose from the engine if I remember correctly). First of all, what is this thing and could it cause my problem if it's malfunctioning? Also, what is it's function?

As a side note, I was trying to figure out how to fix the overheating problem and I was going to add an external tranny cooler; however, upon inspecting the front of the radiator I discovered it already has an external tranny cooler that's connected inline with the tranny cooler inside the radiator. So the tranny fluid should NOT be overheating with both the tranny coolers being used.....correct????

IF that's the case, now I'm leaning toward the "universal" Walmart fluid as being the problem?? If that's the case, would it still overheat (if it's the wrong fluid) even though I have 2 tranny coolers being used? Trying to figure out what would cause it to not want to move the vehicle upon taking off from a start and why is it overflowing through the vent tube.....overheating sounds logical to me. However, I'm just taking a logical shot in the dark here and am hoping you guys have the answers....

Thanks in advance

 

[trashtruck]

for a 94 the dex/merc should be fine but ford IS replacing mercron atf with mercron v, just fyi. ford says it's better. the canister looking thing on the side is probably the vacuum modulator.

 

[1992 Eddie Bauer]

for a 94 the dex/merc should be fine but ford IS replacing mercron atf with mercron v, just fyi. ford says it's better. the canister looking thing on the side is probably the vacuum modulator.

What does the vacuum modulator do? And if it was malfunctioning, would it cause the problems I'm having?

I also just read that overfilling the tranny would also cause it to overheat. Is this true???? I did overfill mine when I first installed it.

 

[hardt]

FWIW, many years ago I had similar problems and it could be because we used the same ATF. I have a "93 Explorer with the A4LD tranny. This was a company vehicle that I used for many service calls to high altitude (14,000' elevation) sites and never had a problem with the transmission. After I retired and purchased this vehicle, as a preventative measure, I dropped the tranny pan and r/r the filter and ATF. I used the same Walmart Supertech ATF to replace the oem ATF. Twice after that maintenance effort, I tried to drive through a pass at 6,500' and both times I lost about 4 qts of ATF within seconds and of course, was dead in the water! Unlike yourself, I never could figure out where the ATF leaked from. BTW, I did use a transmission sealer type solution between the first and second failures but obviously it did no good.

I think this problem happened because of overheating of the ATF at the higher altitude where the lower air density reduces the cooling capabilities. I never had any problems at lower altitudes. So based on your experience and mine, if I ever get the energy to drop the tranny pan again, I will definitely try to get the Motorcraft ATF that was initially used in this tranny. Here's hoping you have good luck solving your problems.

 

[1992 Eddie Bauer]

FWIW, many years ago I had similar problems and it could be because we used the same ATF. I have a "93 Explorer with the A4LD tranny. This was a company vehicle that I used for many service calls to high altitude (14,000' elevation) sites and never had a problem with the transmission. After I retired and purchased this vehicle, as a preventative measure, I dropped the tranny pan and r/r the filter and ATF. I used the same Walmart Supertech ATF to replace the oem ATF. Twice after that maintenance effort, I tried to drive through a pass at 6,500' and both times I lost about 4 qts of ATF within seconds and of course, was dead in the water! Unlike yourself, I never could figure out where the ATF leaked from. BTW, I did use a transmission sealer type solution between the first and second failures but obviously it did no good.

I think this problem happened because of overheating of the ATF at the higher altitude where the lower air density reduces the cooling capabilities. I never had any problems at lower altitudes. So based on your experience and mine, if I ever get the energy to drop the tranny pan again, I will definitely try to get the Motorcraft ATF that was initially used in this tranny. Here's hoping you have good luck solving your problems.

I find it more than just a coincidence that you and I had the exact same problem using the same tranny fluid. Maybe this is the problem??? I just hope I didn't damage the tranny. Maybe I should try Motorcraft ATF (if I can find it) or a good brand of Mercon V and see what happens????

I also find it interesting that you didn't have any problems with the tranny until you changed the fluid. There was lots of people mentioning pros and cons on changing the fluid in a tranny with so many miles on it. Of course there were lots of people on both sides of the fence, which left me just as confused as I was before I started reading various posts....

 

[hardt]

"There was lots of people mentioning pros and cons on changing the fluid in a tranny with so many miles on it. Of course there were lots of people on both sides of the fence, which left me just as confused as I was before I started reading various posts.... "

There was 46,000 miles on the Explorer 15 yrs ago when I had the first failure and 5 years later at 51,000 miles the second failure. Yeah, I don't drive a lot in retirement!! LOL

 

[trashtruck]

the vacuum modulator would control shifting, your symptoms sound more like overfilling but i could be wrong, i'm not great with transmissions.

 

[1992 Eddie Bauer]

"There was lots of people mentioning pros and cons on changing the fluid in a tranny with so many miles on it. Of course there were lots of people on both sides of the fence, which left me just as confused as I was before I started reading various posts.... "

There was 46,000 miles on the Explorer 15 yrs ago when I had the first failure and 5 years later at 51,000 miles the second failure. Yeah, I don't drive a lot in retirement!! LOL

Hmm, that's not many miles to be having problems. Maybe the Walmart ATF is the problem.....hmm, makes one suspicious to say the least.

So what fluid did you use after the second failure? How many miles do you have on it now? Any problems since repairing the second failure?

 

[1992 Eddie Bauer]

the vacuum modulator would control shifting, your symptoms sound more like overfilling but i could be wrong, i'm not great with transmissions.

I assume you're saying that overfilling will cause overheating? I hope this is the cause of the problem. With that said, why did it take so long for the problem to show its face? I haven't taken it out of town since installing the tranny, but haven't had any problems until now, even with the tranny overfilled. This confuses me. One would think that the problem should have happened right away? Am I wrong in my thinking?

 

[hardt]

I used the same Supertech ATF when I had the second failure because I never suspected the ATF. Since then, I've had a lot more exposure on the web with the different car maintenance sites and now have become a little more knowledgeable about the different auto fluids and how they can be different. Yeah, if you can find the ATF that is close to the original and find that it fixes your problem, please post back and I will definitely follow your lead!

 

[1992 Eddie Bauer]

I used the same Supertech ATF when I had the second failure because I never suspected the ATF. Since then, I've had a lot more exposure on the web with the different car maintenance sites and now have become a little more knowledgeable about the different auto fluids and how they can be different. Yeah, if you can find the ATF that is close to the original and find that it fixes your problem, please post back and I will definitely follow your lead!

Sounds good. So do I use the Mercon V fluid that is now recommended or use the Dexron III/Mercon??? Or does it matter? Not sure what to use if I can't find the Motorcraft. If I can't find the Motorcraft ATF, should I use the Lifegard Platinum additive also?

 

[hardt]

Oh, I now have 57,000 miles on the Explorer.

You know, before reading your original post, I never suspected the ATF, so I have not researched for a good replacement ATF. I will try to do a little digging but frankly, I'm getting a little too old ( 76 yrs ) to crawl under the Explorer and drop that pan again!!

I'm just your average auto DIY person, and there are a lot of experts on this forum and maybe one of them will steer us in the right direction!!

 

[1992 Eddie Bauer]

Oh, I now have 57,000 miles on the Explorer.

You know, before reading your original post, I never suspected the ATF, so I have not researched for a good replacement ATF. I will try to do a little digging but frankly, I'm getting a little too old ( 76 yrs ) to crawl under the Explorer and drop that pan again!!

I'm just your average auto DIY person, and there are a lot of experts on this forum and maybe one of them will steer us in the right direction!!

I don't blame you whatsoever for not wanting to crawl under the Explorer again. I'm only 45 and find myself getting tired of doing so much mechanic work as I do. But working on cars is my passion, so it's a can't win situation...until I complete a project satisfactorily that is

Sounds like changing the fluid and making sure it's not overfilled might be my first step in possibly solving the problem, but not sure how soon I'll get to it. I'm right in the middle of another project (actually it's just one of many projects I have going on at the same time), so given it'll take about $65 - $70 just for the fluid, it might be a little bit before I get to it. But I'll make sure to post the outcome once I get it completed.

I'm just a DIYer also. Much respect to you old timer