Tranny temps...WEIRD

[03_Turbo7.3]

so im fartin around in my truck all night, theres 5 of us in it, me,my gf and 3 good buddies, were all around 175-190lbs ( the guys that is ) the gf is little 120 soaking wet with change in her pockets lol, anyways i have my evo edge programmer set on stage 3 like always and 4" turbo back magna flow exaust and DYI intake, truck always runs gets, got temps of like 190 towin last year which is nothing and it shifted awsome, well tonight different story, were doing ALOT of stop go stop go in 4x4, we were towin 2 sleds with my buddies on them behind the truck down some side streets and just goofin around, after like a small 15-20min jaunt to the next location i notice the tranny temps are like 175 and are climbing slowly, i mean were not going anymore then 40mph and hitting everyday red light, oh need i say its also -34 C out side yes i said -34!!!C so thats about -27.4 F lol, FREAKING COLD OUT, so im wondering wtf why are they climbing, so i pay attention to my evo 2 guage and its now at 185, a little further and its at 190, the trucks shifting fine, its not harsh, its all firm, then it hits 195 and im getting worried, the stock guage on the dash is dead center from H-C and isnt moving, then BAM i hit 200 and go WTF and stop instantly, i figure why the hell is it so hot, i get out of the truck while its idling lay on my back and touch the pan, its not really that hot, i can hold my hand on it, so i check the fluid and its good, i jsut replaced the filter and fluid a few months ago, so im thinken WTH nothing seems weird, the tranny temps are going down as we sit there now there at 185 and dropping slowly, and its now -36 outside, it seemed the colder it got the hotter the tranny got, so i turn the truck off, set everything back to stock tunes and start the truck again, everything seems normal no CEL no nothing so i start driving, its at 187 and just sitten there, i get down the highway abit doing like 65MPH and all is well its not going up its staying at about 187-189 and dropping going down hills, it hit 190 after going up a a long hill, drove about 25min home and it didnt come off 188 idled in my yard for a bit and it hit 180 and kept going down, now my question is WTFFFFF!!! i dont get it, it shifted great, didnt lag MAN NOT HAVING THE CHIP ON DOVE ME NUTS SO SLOW LOL, temps were fine after and it ONLY happened once this HUGE cold snap happened tonight, last night was only -20 and the night before -14, is it cause of the cold? is it protecting itself? the stock guage didnt even move from the middle? am i worrying about something i shouldnt be??? any help would be great!

[cchase]

well first, the stock gauge is more of an idiot light, I dont believe it actually goes up with true temp, more goes red when its already to hot.

city driving with 4x4, is what makes your trans the hottest, less airflow. I dont think I would worry to much, see if it does it again.

[NCHornet]

No!!!! You have a problem, 4x4 isn't going to raise temps, the slower movement will, but even when you were up to normal speed the temps remained way to high for the ambient temps you reported. My trans gauge won't even register until spring!!!

First of all forget the stock gauge it is worthless. Average trans temps are 70-90 above ambient temps, this will differ with below zero numbers, but you for sure have a problem. My guess is your bypass line. If you look on the pass side of the trans you will see a metal line that runs from the out line to the coolers ( the forward most line) to the return line, there is a spring type valve where is attachs to the out line and if it senses pressure in the line to the coolers it will bypass the coolers and simply plumb back into the trans without cooling. In order to troubleshoot get the trans up to temp and grab that bypass line, if it is hot you found the problem. I would bet a C note this is your problem. They cost about $70 US money. You did good by having a aux gauge, if you trusted the stock gauge you would have toasted your trans as it won't go to red until temps hit 280. You didn't do any damage. Check this line and see if I'm right. Dieselsite seels a kit to eliminate the bypass, but I would just replace it, it is there for a good reason!!!

NCH

[03_Turbo7.3]

ah great lol, i have 218 500km on her too by the way, i have to drive it to work tomorrow and thats only a 20min drive tops and its supposed to be -34 tonight again so we'll see how high the temps get, before in 4x4 going down the highway at 60mph it wouldnt go over 125-130 ever, i knew like 210 and above was catastrophic lol thats why i stopped, id rather not put a trans in my truck, the trucks back on stock tunes for now until i can figure out what it was....*sigh* its never ending lol

[03_Turbo7.3]

and, what do i have to replace ? the bypass line if its that, im wondering if the fluid was so cold it stopped it from going through the cooler?? too much pressure or someting??

[03_Turbo7.3]

so i went outside and started my truck, says -8F on the tranny temp guage its FREAKING cold out here

[NCHornet]

First of all 210 isn't catastrophic, I wouldn't get concerned about damage to the trans until 230++++ probably more like 250, the oil will break down rapidly over 230, but 210 means you have a cooling problem but it isn't pending doom.
Yes if the bypass line is warm you simply buy a new bypass line it will come with the new valve in it.

NCH

[tubular031]

I am with NCH here. Ill bet you its the bypass valve

http://www.dieselsite.com/index.asp?...ROD&ProdID=172

[layson]

If you are going like 10-15 mph the tranny is going to get hot if you are pulling something or going up a real steep hill. I don't think the torque converter is locked so the tranny gets hot.

Where you in 4x4 high or low. I think low locks the converter? I am not sure about that.

[symbols]

ah heck, I wouldn't worry about it until you see this


Just kidden. Sounds like NChornet has you lined out