Tranny temps

adamsdaddy · Nov 15, 2020

Pulling a 3,500 lb popup trailer in 100-105 outside temps had me hitting 238 . Had the transmission fluid changed at 50,000 and it was quite black. Had the auxiliary transmission cooler added and now I’ve never seen it go above 212 on short steep grades while towing. Perhaps next July we’ll head out to the Kern River and experience the same weather. That’ll let me repeat the conditions.

lbv150 · Nov 16, 2020

max78 said:
The 6R80 transmissions have a thermostat (Thermal bypass valve) built into the transmission. That's because cooler fluid is not always better for a transmission. These things are designed to operate at a specific temperature. Ford Tech M(whatever) has a good video about it. That's also why he said if you pay for a "flush" on these you got scammed because zero fluid will flow though the actual transmission due to the valve. The valve is closed until its up to temp. He also said it will never get up to temp just idling.

If you saw low temps on your trans I would be worried, obviously too high of a temp is worrisome as well. 230 is not bad when under extreme pressure, IE hauling a trailer up a long grade.

The 150k trans service is is from the marketing department, not the engineering department. Fluid brakes down and needs to be replaced before that. There is a lot of sheering nd clutch wear in a transmission, and that debris needs to be removed.

Dabigguy · Nov 16, 2020

How do you check transmission temperatures? Is there a way to check it on a 2010 Expedition?

catmandu · Nov 16, 2020

2017 no tow package. Last month, I did a cross country tow right at max GCVWR but above recommended frontal area (7' tall enclosed 7x16 trailer). 210*-220* seemed normal. 230* on a long incline, at which time I backed off a bit, 230* and climbing at speeds over 75. I forgot to fire up the OBDII monitor after one fuel stop, got into limp mode accelerating to speed up a slight incline, 270* and falling slowly by the time I pulled over and was able to monitor it. 75k miles now, tranny drain and fill in my near future, might have to go to Bangkok for that (that's for you, @69Rustang

)

Belias21 · Dec 2, 2020

Following up for anyone interested...
On our trip to Pigeon Forge and back (from Charlotte), the temp never rose above 212. At that, it only stayed there for a minute and that was on a long, steady climb.
Ambient temp was a bit cooler (in the 55-60 range), but I’d call this a significant improvement over my pre-transmission-cooler experiences.

Adding the cooler was definitely worth the $150 and 2 hours it took to put in!

lbv150 · Dec 2, 2020

Belias21 said:
Following up for anyone interested...
On our trip to Pigeon Forge and back (from Charlotte), the temp never rose above 212. At that, it only stayed there for a minute and that was on a long, steady climb.
Ambient temp was a bit cooler (in the 55-60 range), but I’d call this a significant improvement over my pre-transmission-cooler experiences.

Adding the cooler was definitely worth the $150 and 2 hours it took to put in!

Can you post the part numbers for the cooler parts and how you installed it and what year is the Expedition?
Thanks.

07navi · Dec 2, 2020

lbv150 said:
Can you post the part numbers for the cooler parts and how you installed it and what year is the Expedition?
Thanks.

I think those are already in here.........do a search.

Michael McC · Dec 2, 2020

Always tow in manual. Don't let the computer choose your gears. Shifting is what heats them up. I've been towing horse trailers in hot climate against heavy winds for years in my 2016. No extra trans cooler. Never seen a trans temp over 215.

I did drop the trans oil pan and replaced fluid at about 75,000 miles. It didn't look too bad. Put about 7.5 quarts back in. Will do it again at 120,000 or so.

Snidley53 · Dec 2, 2020

Drove out to Colorado and back from Southern Indiana went through Wolf Creek Pass with weather temps in the '60s and saw a high of 210 on transmission temps towing a 5600# camper. After hearing others talk of seeing much higher temps I was pretty pleased.

mjp2 · Dec 3, 2020

Dabigguy said:
How do you check transmission temperatures? Is there a way to check it on a 2010 Expedition?

I just noticed that your question was never answered. Transmission temp is one of the many values that can be pulled via the OBDII port on the truck. Most OBDII scanners will expose the data available.

I keep a ScanGauge II mounted on the dash to monitor transmission and engine coolant temps in realtime while driving.

Tranny temps

adamsdaddy

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