Help! ATF leaking, but from where?

I did a transmission flush this past weekend. No problems the last few days of commuting to work. Today, I get to the exit and I see smoke coming from the bottom of my truck. I get to work and crawl underneath. There's ATF all over the front part of the driveshaft. I can't figure out where it came from because the fill hole is on the opposite side. Is there an overfill/breather that the fluid came out from?

I used an OBD tool to check the fluid temp. I checked it when it was 123F. It was down about a quart and a half, so I filled it until fluid came out. Then I shifted through all the gears. The fluid temp was still around 120.

 

I think it's coming from the Driveshaft seal. I'm dropping it off with the dealer today.

 

If you did the transmission flush yourself, do you think the dealer will cover the leak?

 

So you have a 4x2 Prerunner? How much rear lift are you running?

 

A tranny flush on a low-age vehicle should not cause external leaks. And OP doesn't have to tell the dealer about the flush.

 

It's a 4x4. No lift.

 

If you did a flush, where did you extract the fluid from? At the radiator?

 

Yes, I turned the truck on and let it pump out a few quarts at time. Refilled in the fill hole.

 

How can the transmission be leaking from the driveshaft seal on a 4x4? On a 4x2 Prerunner, yes, but 4x4s have a transfer case between the transmission and the driveshafts.

 

I think you may have a leak at the hose connection where you flushed it.

Why are you flushing the transmission on such a young truck?

 

I'm pretty sure he is talking about the propeller shaft seal.

 

That seal would be on the transfer case.

 

There is a shaft that goes between the front differential and transfercase. That shaft got soaking wet with ATF. I chose to do the flush because it just turned 36k and I have been reading that the transmission may have come low on fluid. The past few months, the truck would shift way too soon and it was never a smooth shift.

 

If the front driveshaft was never covered in ATF before, then you need to retrace your steps from the flush. Unless you drove over something funky there is no reason why you'd see what you're seeing.

 

It's already at the dealer. thanks.

 

theres a breather on top of the trans. what probably happened is that you over filled it and when the it got hot the fluid expands and has to go somewhere and it went out the breather. i work at a dealer and seen it before.
theres a certain way you have to drain and fill the fluid . and if your draining hot trans fluid it will be more then if it was cold and most people dont think of that so its common to over fill the trans.

 

OK. I was just trying to clarify what he was saying...

 

I saw where you said your rig is at the dealer. I'm interested in your resolution.

As far as I can remember there is a breather for the transmission. It's in the engine bay, and I believe it's almost dead center of the truck, behind the motor by the firewall.

 

Crom inquired about the outcome last week.

What happened?

 

The transmission was over filled and fluid came out of the breather. There must be a problem with the calculation I used for the PID I used for the obd app. I'll use the pin jumper method next time.