Transmission Overheat and Leak

[Redram99]

Hi All.
I am posting this for my step dad. We have a mysterious problem.

He has a 2002 F350 Diesel Auto.
The other day we were out hunting bison here in northern BC while it was
-40C and while we were cruising around the transmission overheated and started to puke ATF out of the bell housing.

I thought that the front seal on the tranny had let go. The tranny was working fine while leaking, hadn't slipped or done anything strange.

Anyways, we hitch hiked to the nearest truck stop to wait for a buddy to pick us up(all the while I was riding my stepdad like Seabiscut about his Fing Ford...I drive a Duramax). Anyways long story short we happend to run into a guy while waiting and he said his did the same thing once and never leaked again once it cooled off.

So the next day we returned armed with my truck, a big trailer(to haul her back, ATF, heaters and tarps. We got her fired up, filled it with Tranny fluid and drove it home, and it never leaked a drop. Works Flawlessly!!

I think what happened was the tranny cooler froze off/gelled and then the trans couldn't circulate the oil which caused the trans to overheat and there must be a pressure relief on the ford tranny which bleeds ATF?

Has anybody heard of this?
Could there have been any seal damages?
We put in about 5-6 L (1.5Gal) of ATF.
Thanks for your input.

[vegginpsd]

I too would like to know too. I have had by second cooler gel up and cause the trans to bypass the coolers.

[SuperCrutyPS]

There is a front seal on the tranny. I was towing my 5th wheel(12K) and once my tranny got hot, it puked fluid from the bell housing. Cooled off over night, went sight-seeing (not towing), no leak. But it did do it on the way home. Took it to a tranny shop and they replaced the front seal. They said it's a common issue with these trannies. Hasn't leaked since and I have towed my 5er on some pretty hot days.

You may be onto something thinking the cooler got too cold and didn't allow circulation. Have your dad keep an eye on it....Now that it's been hot like that the seal may be weakened.

[NCHornet]

They have a new updated seal for the trans, and having one puke when they get warm is not uncommon. The 4R100 has a bypass line that is on the pass side of the trans and runs between the line to the coolers and the return line, if it senses pressure ( not temp) it will open the bypass valve allowing the fluid to not run through the cooler and simply return to the trans where it will get very warm quick. My guess is under those temps the fluid was so cold it couldn't flow as if it were warm so the bypass opened and returned the fluid back into the trans. I would flush with new fluid ( only Mercon/Dexron III) and keep an eye on it.

[Redram99]

Thanks for the input.

So what I get from this is there is no pressure relief that let the fluid out. It would have pushed fluid past the front seal which should be replaced?

Thanks