xMUDKINGx

Anyone else ever see their trans temps this high? Granted I was driving 75-80 MPH up hill for probably 15-20 minutes so it didn't alarm me. Just wondering?

redfishtd

I am studying my cooler temp in front of condenser after servicing trans . So far it only went to 160 . I hear that the trans wants to run around 200 to keep fluid flowing ,it has its own thermo . . Your radiator loop is going to follow engine temps so around 195 on the thermo or below .
Heat destroys transmissions I would not like 225 for any length of time . I don't have one of those readers to monitor my trans temp but I'm thinking about it .
I tend to back down on mountains and not push it because of overheating in past vehicles . .I have the tow package and the good cooler up front . Its terrible hot in fl now and i just serviced my cooling system ,used distilled water and 50 percent antifreeze , I read to use only 40 percent in very hot climates no more than 50 percent .
What color is your trans fluid running at now .
I would buy these monitors in a minute if they could give me oil pressure which they can't .
I guess you really need some input from those that are running the testers .
05 5.4l 3v supercrew work truck . 4r75e trans

powerranger262

225° seems a little hot. I would check out the codition of your trans fluid, change it and your filter if it's burnt.
I've always heard that 100° over ambient temps is normal.

connorfx4

I would change your fluid and filter. Too hot IMO. Should have slowed down a little over the big hill. Hopefully you didn't hurt anything.

techrep

iTrader: (1)

Hit that several times while towing in the hills.. It always cooled back down right away .. I changed my fluid after that trip.. It still looked fine.

dom07

Look at all the temperature charts found with a google search of "transmission fluid temperature"

I would examine the fluid, and compare it to new Mercon V. If it smells burnt or is very dark, change it. But I don't believe that 15 miles at 225 degrees is anything to worry about. If you regularly do this, a separate fan/cooler is probably a good idea to keep temps below 195.

My alarm is set at 190 degrees. Full flow through the coolers happens by 180 degrees (trans fluid thermostat is fully open), and the 4R70W/4R75W will last the longest at temps 180 or below.

redfishtd

At 165k and engine reworked I have to get ready to chose a trans remanufacter . If it goes I want the upgraded version from a good reman . We have a guy locally but they usually don't warranty anything very long and they are expensive . So far I have learned the forward drum on my 05 5.4 4r75e trans is a weak spot . It is recommended to go after market on that part, pining a reman down on those points is hard to do . Some don't change out items they should .
Jasper is expensive and only sells to dealers . I ruled them out on engine change out and won .
I may start a thread on this . I changed pan to one with a drain on it for its second fluid change . I have the tow package and good cooler but I doubt if I can get another 100k out of it from what I read .

xMUDKINGx

it was 108 out here in Northern California, so I wasn't shocked to see my trans temp soar a bit

joe mcmillan

There are different size trans coolers available on the trucks.
The larger size is 10 rows. Just pop your hood and take a look at the size.
I doubt that you have done any serious damage with one trip to 225 degrees.
If you are going to be towing in conditions such as these, you should consider a larger trans cooler.

xMUDKINGx

I have an XL with a tow package, it used to have a 10 row cooler, but I got my trans rebuilt and stepped up a couple notches, the shop said the OEM are inferior to the one they put in there (now right in front of the radiator) thermal bypass was also deleted. I'm not all too concerned about it. My truck is also lifted 4 inches on 35's. I know this doesn't help the trans temp which is why I had some goodies stuffed in there.