trans temp question

[dbailey1111]

I will be towing through the mountains in a couple of weeks and was wondering what trans fluid temps should be. What temp should I never go above etc. I guess i'm needing to know what is the fluid temp orange and red lines. I think it's synthetic fluid or that's what I paid for when trans was serviced 10,000 mi. ago.

[Jables]

130-150 is great. Things start to go downhill above 200.

[SAD]

It's not so much what specific temp is the "red line"... But it's the temp over time.

For example... 130-150 is pretty standard for level highway cruising with a locked up torque converter..

Run up on stop-and-go traffic and that will change very quickly. 170-190-210 wouldn't surprise me at all.

Back into an uphill camping spot that requires some maneuvering, and 250 would not surprise me either.

Climb the Vail Pass and I would not be surprised if you saw 250-280...

You dont simply change the fluid because it "saw" 280 degrees... @ 280 degrees it as a reduced life. Meaning, it's only good for so many miles. When doing that parking maneuver or climbing the mountain pass, how many miles did you run, or how long duration was it at that high temp? Not many and not much.

The best use of a transmission temp gauge is to detect trends. Pay attention to what's "normal" for your towing conditions and use the gauge to detect deviations from that norm - which might indicate a problem.

Change your fluid at intervals appropriate for the type of service your vehicle is subject to... And don't get overly concerned out about the occasional high temperature.

[Hansel]

Tow vehicle info would help, does you truck tell actual temp or is it a idiot needle that just has a safe range then goes into a overheat range?? I have a 2000 F-250 7.3L powerstroke that I upgraded the trans cooler from one that they used in the 6.0L powerstroke and my trans temp has not gotten over 150* but it hasn't gotten into the summer temps yet so I'm sure it will climb alittle higher.

[Jables]

Originally Posted by Hansel

Tow vehicle info would help, does you truck tell actual temp or is it a idiot needle that just has a safe range then goes into a overheat range?? I have a 2000 F-250 7.3L powerstroke that I upgraded the trans cooler from one that they used in the 6.0L powerstroke and my trans temp has not gotten over 150* but it hasn't gotten into the summer temps yet so I'm sure it will climb alittle higher.

Just remember that 6L cooler cannot ever be flushed, they get changed out when your 4r100 packs up. I usually install a Trucool 4739.

[440justin]

I have a 2012 F150 and it likes to run at 195 all the time, city, highway (no load) highway (with camper) and even up hills with the camper (and yes I have the tow package with the tranny cooler). In fact my owners manual states that 195 to 215 is the normal operating range for the transmission. Now my old Chevy would never run more than about 150 in town and on the highway and about 190 when loaded up.

So I think the answer will depend on what kind of truck you have.

[dbailey1111]

2006 f-150 5.4 HD with tow package. Has trans cooler and edge programmers. Programmers shows TXT and usually runs 140-150. Just wondering what is too hot so I could pull over and let it cool instead of roaching the trans.

[tileman]

I have a 2010 dodge 3500 diesel with auto and 3.73 rearend
Our trailer is a 2012 fuzion toy hauler. Gross weight 23,240

Last year when we were towing it was around 109 outside and the truck temps motor was around 210-215 Transmission was 170-185

I tow in 5th gear and run around 2,000 rpm to 2,200
and get about 10 to 11 mpg. All stock truck and I think that great mpg.

Ron.

[440justin]

Looks like 150 to 170 is the "normal" range for your truck (Page 306). As others have stated you can be higher than that when towing.

http://www.motorcraftservice.com/pub.../06f12og4e.pdf

[Hansel]

Originally Posted by Jables

Just remember that 6L cooler cannot ever be flushed, they get changed out when your 4r100 packs up. I usually install a Trucool 4739.

What are you talking about???

If my transmission breaks again, which it did at 194,000 miles, I wouldn't want a flushed cooler, I'd want a brand new one. But you can flush a 6.0L cooler if you want but I wouldn't recommend that too anyone.

[Corbin1357]

I have a 2005 F150 FX4 run an edge and have the tow package, I run typically around 160-180 towing. Last summer in the black hills I hit 202, but it was hot out! Like the others have said it is more about how long the trans fluid will last. Happy Camping!!

[fjr1300]

Hot Rod Magazine has a good article on auto trans cooling. It includes a graph showing fluid life versus fluid temperature.

http://www.hotrod.com/techarticles/g...s/viewall.html

[raytronx]

Also depends where the temp is being read from. Mine is in the pan so it's going to read cooler than if the sensor is located where the hot fluid exits the transmission before it sees the cooler.

My tranny temp gauge is generally around 140-150, except on hard pulls it can hit 180, if it climbs near 200 I pull over and let it cool. But that's with temp sensor in the pan, coolest spot.

Best to get to know your truck and get a feel for what is normal.

Ray

[Jim W]

My truck runs between 160 and 180F on a level highway and as high as 220F in the mountains pulling in five gear at 2000 to 2200 RPM’S. A lot depends on gear ratio of the differential, transmission ratio, tire size and how many coolers are on the truck. I watch Boost pressure, EGT’s and transmission temperatures when I am pulling in the mountains trying to balance all three against known limits of operating ranges. I will shift between 6th gear and 5th gear depending on the three mention gauges as I read them.

I have my truck set up for towing with Mag-Hytec front and rear differential covers and a Mag-Hytec deep transmission pan that add 2.5 quarts more oil. They are AL with deep fins on them for added cooling also the transmission temperature sender is in the pan.

All modern transmission fluid is good for continues operation up to 250F (ATF+4) and the fluid overtime will not degrade. But the Buna-N seals that are use in the transmission will fail overtime if the temperature is over 250F for some time and the case is heat soaked. I believe the CEL/idiot lights will come on at 260F if this temperature is hit for some time.

Jim W.