Transmission temperature max of 240 deg. sound right?

[Oklahoma_Dan]

I am doing a double trailer pull (5th wheel + Can Am Commander)in Colorado with my 7.3L diesel F250. Having just installed a larger trans. cooler with a temperature gauge I was told that I should keep my transmission under about 240 degrees. For those in the know, does this sound about right when you are doing a hard pull up a steep grade?

[overthehillbill]

kampinguru wrote:
I have a 2000 7.3l F250 and have had the 6.0 oil cooler installed. You do not want to be at 240 for very long. Check the smell of your tranny fluid on the dipstick. If it smells burned, you have been too hot. I also have the BTS transmission installed and I do not see temps above 160 anymore. I run Scheffers synthetic fluid in the truck as well.

X-2. I have the John Wood Towmaster tranny with the 6.0 tranny cooler.
The stock 4R100 tranny is the weak link if you are towing heavy.

[Oklahoma_Dan]

Thank you for all of your replies as well as the in-depth research. You guys are great. When installing the larger trans. cooler and gauge I also had them flush completely the transmission, put in a new filter and put in BG brand synthetic fluid. The old fluid (about 12,000 miles old) was a little off color which prompted me to make improvements during this vacation. Once I am home I may go to a deeper pan as well. All good suggestions.

[Miles_Away]

I don't know that synthetic oils run cooler, but they are more tolerant of higher temps. Using them is good advice. Temps in the range of 240 when pulling a long grade with a load (trailer) are not uncommon, but they should drop back to 200 or less on level ground. I went to a deeper oil pan to increase my oil volume (3 extra quarts) and a larger tranny cooler which has helped. Make sure your cooling stack is clean and your fan clutch is working properly.

[0rion]

you can also get tranny coolers that have fans on them......not sure if a deeper tranny pan is offered for your truck but if it is I would run the deep pan.

[lillyputz]

I also run synthetic fluid and installed a deeper oil pan on my 3500 dodge.

Lillyputz

[MTPockets1]

0rion wrote:
if it spiked to 240 on a hill and then came back down I wouldn't worry about it a whole bunch but I wouldn't want it to run there for any extended amount of time.

. My temp will climb to 240 on long uphill pull, then drops to 200 or less on level or downhill.

[kampinguru]

I have a 2000 7.3l F250 and have had the 6.0 oil cooler installed. You do not want to be at 240 for very long. Check the smell of your tranny fluid on the dipstick. If it smells burned, you have been too hot. I also have the BTS transmission installed and I do not see temps above 160 anymore. I run Scheffers synthetic fluid in the truck as well.

[el_Rojo]

Change to synthetic fluids. They will run cooler.

[Puddles]

If your truck is a 2000 or older, Ford has a radiator available that will alow tranny oil to go thru it and be cooled... does a much better job than a air type cooler... I wouldn't like to see oil temps above 210 anytime. That cooler water in the bottom of a radiator is a life saver for the transmission.

[0rion]

if it spiked to 240 on a hill and then came back down I wouldn't worry about it a whole bunch but I wouldn't want it to run there for any extended amount of time.

[cpaulsen]

In your 4R100 trans...it should not be run @ 230 for any extended length of time. Check out the FTE forum. There is a trans engineer who posts there...Mark.

[Old-Biscuit]

IIRC the OEM factory high oil temp alarm is 250* on my RAM

Hard pulls, high air temp and long grades I've never seen temps over 215*F
Had OEM alarm once backing 5'vr up long steep driveway...gauge reading 245*F

Found this on another forum.......posted back in 2011
Maximum transmission temperature

In the February 2011 issue of Trailer Life magazine RV Clinic in response to a reader about the maximum transmission temperature allowed in a 2009 Chevy Silverado, the Tech Team had this response.

“General Motors’ in-house towing team expert provided RV Clinic with this statement: The maximum allowable automatic transmission fluid temperature is dictated by the transmission oil itself. The oil begins to degrade significantly above 270 degrees Fahrenheit, so we design vehicles so that in all but the most extreme conditions, the fluid temperature in the transmission sump stays below 270 degrees F.

We allow for up to 285 degrees F in extreme conditions (i.e. towing a trailer with combination loaded at GCWR in Death Valley). But for customer usage anywhere else in the country, even at GCWR, transmission sump temperature should stay well below 270 degrees F. Above this point, certain internal components, such as seals, begin to disintegrate rather quickly. Although newer synthetic fluids can withstand higher temperatures we still recommend this (270F) as a maximum temperature. "

And this also was posted.....
a little research thinking that maybe GM was referring to new vehicles that are utilizing synthetic oil as all GM trucks do since GMT 900 in 2007 (much higher operating temps than traditional "dino" oil). I found that transmission oil starts breaking down prematurely at temps above 175, damage occurs above 300 to internal transmission components, and as high as 275 is allowable for all transmission fluids. However, it you run temps above 175 (as we all do towing our rigs) more frequent fluid and filter changes are required as outlined in the following chart (validated from a couple of sources):

175 degrees change every 100,000 miles
195 degrees change every 50,000 miles
215 degrees change every 25,000 miles
235 degrees change every 12,500 miles
255 degrees change every 6,520 miles
275 degrees change every 3,125 miles

[pronstar]

Depends on the situation.
In city driving when the torque converter is unlocked, that should be your ceiling.
On the highway with the torque converter locked, that's way too high.

[ScottG]

A high of 240 isn't bad.

[blkdodge]

Seems high to me. I run around 200 degrees