Trans temps when towing...

[johnboneske]

I got my Torque Pro and dongle installed in my Expedition. Temp outside was about 84 degrees, I was towing it today, for about 25 miles. The hottest I saw was 183.4 degrees, and that was going up a hill and under acceleration. Most of the time it was around 170. Solo I get about 160. I installed the two sensor PID's that seem to work, from the Ford downloads. The sensor 1 and sensor 3, sensor 2 does nothing for me... One is lower by about 4 to 5 degrees constantly. I will "assume" the lower one is the fluid going into the Trans, and the higher is the fluid coming out of it? The temps I said here are the higher ones.

How hot is to hot? Should I install another trans cooler? I have the factory larger one, not the tiny one. But, the external cooler is run in series with the other cooler that is built into the radiator. Should I bypass the one going into the radiator? Any help would be appreciated!

 

[17LimitedExpy]

Here are 2 links that discuss transmission temps...basically 200F is the highest you should normally see, but it can go up to 210-230 temporarily with little (relative) effect.

https://www.etrailer.com/question-61011.html

http://www.txchange.com/heatchrt.htm

I believe I have read somewhere the temp of 240 being the highest it should go...something about that temp breaking down the fluid at a very high rate and then causing life-shortening damage to your transmission...and it doesn't matter the manufacturer.

 

[Big Brian]

you are fine

 

[1997SCEBFEX]

++ on being o.k.

there are lots of charts on the net which show projected trans fluid life commensurate with operating temps.

I routinely changed my fluid and filter every 25K when cross-country towing.

 

[coolzzy]

The 6r80 (used in the 10+ expeditions I believe) is designed to sit between 198 and 205 for regular unloaded operating temps. It is thermostatically controlled and doesn't even allow the fluid into the transmission oil cooler until around 200 degrees. I've seen it as high as 235 climbing a steep slow mountain road with 6200 pounds in tow (using a 12 F150 5.0 truck). My 10 5.4 F150 never went over 200 but had max tow and bigger engine radiator. My ecoboost expedition hit 208 last weekend in a similiar situation but quickly dropped to 203 after the hill.

 

[ChrisRCNY]

From everything I've seen, 07+ expeditions have overkill trans cooling. I've yet to see anyone post numbers that are truly excessive when towing within the rated trailer capacity. I've also not seen any substantial changes in temperatures when people have added bigger coolers.

The thermostatic control keeps them nice and stable, but I'd love to have a gauge showing how open that valve is...

 

[FurryFord]

I’m traveling from Montreal to Florida in 2 weeks from now pulling our TT, dry weight 7500lbs, as well as all our gear and family (my wife and our 4 kids) I did a run to the scales to do some final adjustments to my hitch and weight distribution, tipped in at 14,800lbs GCWR with nearly 50/50 distribution on truck and trailer. I’ll let you guys know exactly how the Expy will do trans and engine wise. I know my old Yukon XL would hover between 203-212 but in all fairness I would drive nearly 21 hours straight only stopping for gas, food and bathroom brakes!