Clogged Transmission Cooling System (Automatic)

[Ardy]

Was driving on the highway for a few hours on a hot day.

Transmission got up to 120C and fluid started coming out of the vent valve on the case.

I refilled the transmission fluid and it hasn't leaked any since.

I do feel like my transmission gets up from 25C (ambient) to 80C quicker than it did before so I am suspecting a clog in the transmission cooling system.

Anyone experience this before or have anything to share?

I'm just gonna throw a new trans oil cooler at it and see if that fixes it otherwise. Unless there are some common issues others have had.

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[Skye]

Spoiler: I have zero experience with Ford automatic transmissions.

Miles, KMs on car?

Has the transmission ever been serviced?

Any seals leaking anywhere?

The trans gets up to temps quicker than before. For how long has this been occurring?

Is the transmission otherwise operating correctly?

How long was the car driven at peak temps, on the day of the overflow event? I'll let others with experience answer, but if it was me, I'd service the transmission afterwards. The system was boiling over; that couldn't have been good for the fluid which remained.

By clog, do you think externally, the fins have become filled with road debris, bugs and other bits and causing it not to cool as well as before? Or, do you suspect it is clogged internally?

The former, I could understand. Being a closed system, if we think the latter, I'd be concerned about that. If you think there's been an internal restriction, I'd want to find out why that happened: if the trans is shedding a lot of materials and the fluid (or lack thereof) has caused something else to occur.

 

[gone_n_60]

is this the 10R80? I had issues like that at the track and under warranty Ford Dealer replaced the Valve Body. All good now.

 

[Ardy]

is this the 10R80? I had issues like that at the track and under warranty Ford Dealer replaced the Valve Body. All good now.

Did the car have any symptoms when driving it before the fluid overheated?

 

[Ardy]

Car has 75k miles, only service to transmission was fluid and filter at 30k miles. There's no seals leaking and it operates normally until it overheats (which I haven't been able to replicate since either). I don't think it got damaged during the overheat event. I noticed well before the critical temp and it only lost 1qt before I pulled over and topped it off.

I'm unsure what to "fix" now since it's operating fine but there was obviously a major issue that day.

How do I test the flow rate through the transmission cooling system? Is it safe to disconnect the line coming back from the cooler at the location where it goes back into the transmission and turn the engine on for a few seconds to see the flow?

 

[gone_n_60]

Did the car have any symptoms when driving it before the fluid overheated?

On the track things happen fast. Each time it spit fluid out the vent the transmission was up to 235F or more. You know fast because your leaving a huge smoke trail from fluid going right on to the exhaust, and you get black flagged.

btw you must have some skills to "top off" trans fluid just pulling over. ;O

 

[S550HPP]

Ford replaces two coolers on my car while trying to solve delayed P - R shift once on valve body overhaul, once on CFD rebuild....must have been some defects.

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