Was reading this thread:

https://www.dieseltruckresource.com/...ssion+temp+low

And I thought what a great idea to install a second "temp sender" to a switch on the dash to go between my pan sender, and the Hot line out of the trans.

So... I'd like to install a second sending unit in the hot line... to be able to see how hot the trans fluid is coming out of the trans vs. the pan temps. Currently in 85* F weather, I consistently run 145*F or less, regardless of where I am... In traffic, on the highway, or just tooling around town.... I haven't had the opportunity to run it with a trailer for a significant distance, so that I have no Idea what it runs.



Can someone tell me how to identify the hot line out of the transmission, or should I just drive for a little while, pull over, and stick my hand in there too find out ? I assume it's the "forward" facing tube the hot fluid is sent from ...



TIA

 

I have read the discussions previously about sender location temp differences. It seems some say temp at the pan is of no value because overheated ATF can be cooled back down to acceptable levels by the time it gets back to the pan. I just can't imagine circulated fluid that is say 240 degrees out the hotline gets down to an acceptable 180 average at the pan. At a minimum, it would be nice to know an approx reference point conversion that can be a guide for those that have one sensor in the pan. Kind of like having an EGT probe in the downpipe versus the exhaust manifold. If the egt gauge is in the downpipe add 300 degrees to the reading type of logic. I am very curious to see what readings you get if you do get that second sensor in the hot line.

 

Front line is the hot line and rear is the return line, If i was to install 2 temp sensors i think i'd install one in the hot and one in the return to see exactly how much cooler the return fluid is,

 

I already have one in the pan, as I'm one of the lazy guys that got the derale pan that already had the bung welded into it for the sensor. I'm perplexed as to why the pan readings never really go over 145* while driving. Granted I haven't been stuck in traffic for 4 hours sitting there, not moving much at all, but I think the only time I saw it reach 160* was once. and that's when the truck was sitting idling in 90* weather for about a half hour keeping the interior cool with the A/C on...


I guess it's something I need to think about doing ... In the meantime, I'm going to use my infrared non contact sensor to see what it reads after driving for a while... to hopefully see if the gauge is reading approximately the same or not.

 

Not sure if you have read this but thought you might enjoy...

http://www.cumminsforum.com/forum/94...-location.html

Many have reported good results with this sender line adapter. I will be buying this when I get around to getting gauges in:

http://www.genosgarage.com/ACU-TEMP-...UTEMP_ADAPTER/

 

Thanks Sooty,

I wonder what the deviation between the actual internal fluid temperature and the outside of the tube really is, especially during winter months, traveling @ 55 MPH.

 

Someone running it on a 3rd gen truck reported in a thread there turned out to be only a few degrees difference between running the sensor in fluid at the line vs running their sensor with the adapter on the line. Close enough for me.

 

I have my sensor in the hot line and regularly tow heave, if i don't pull it out of O/D i can peg a 250* gauge, even towing a empty 25ft goosneck i will maintain 210-220* on flat ground, and thats the same with my truck camper in as well.

i am contimplating moving my sensor to the pan as i also have no acceptable referance numbers to go by.

i have had it this way for a couple years and so far so good.

Darwin

 

Perhaps 250 + at the hot line is not too much as long as the pan temps and returning fluid temps are in a more reasonable range. One member liked just monitoring the cool return line. His logic was, the TC/hotline temps are going to be HOT when towing heavy but what is important is that the cooling system is doing its job and returning cool working fluid and thus maintaining reasonable pan temps. So, without good absolute numbers to live by for all areas of the transmission it is hard to get real comfortable in my opinion. I like the idea of being able to easily switch the sensor adapter between the return and hot lines for some trips to gather data and see the relationship between the two. That would allow one to see the effectiveness of the trans cooling system and the difference between hot and return temps without multiple gauges or hardwiring in multiple permanent sensors.