Trans Temp question

chris

chris

cltdba
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Joined
Sep 28, 2009
Location
Concord, NC
I just bought a superchips programmer for my 2003 Dodge Ram 1500 (hemi). My primary use for the programmer is for towing purposes and to squeeze some more MPGs out of the truck while empty. Additionally, I like that I can view more diagnostic data with it. In particular, I'm interested in the transmission temperature because I keep getting the check engine light while towing and the code is related to the transmission temperature. It pulls fine, just throws the code. So anyways, long story short, I'll be towing the Jeep to Harlan this weekend so this will be a great chance to test it out.

My question is, what should the transmission temp be at? After doing some real hard test runs on the truck last night with the performance program my temp was around 150 on average. I'm sure towing will make this increase, but at what point should I be concerned?

Also, is there anything you guys know that I can do to my truck to help keep the tranny cooler? Possibly upgrade the cooler? It does have the towing package on it and my gear ratio is 3.92.
 
I have read that a stand alone trans cooler will help (not the one that is integrated with the rad). Towing, my trans can see 190 degrees(depending on ambient temps), and if it was to go over 200 I would back off, maybe thats a little conservative..
 
Thank you for the advice. I thought mine had an external cooler, but you may be right in that it is tied in with the radiator. I'll have to see what is available in the aftermarket world.
 
my tranny temp hit 200 last weekend towing to harlan and ive got a 2500 with a cummins and a bd diesel tranny and converter. mine never gets above 150 around town. you will probally be 200+ on some of the long pulls.
 
Also at 220-225 ATF starts to break down, decreasing the lifespan. Just find teh biggest external cooler you can.
 
i would recommend a bigger cooler. stock coolers(external) are a cheap design. you can buy an aftermarket cooler that is of the same size and it will generally have more fins per square inch.(which disapates heat quicker). i strongly suggest to most of my customers who tow, that they upgrade their coolers.
for every 10deg you lower your trans temp, you double the life of the fluid. for every 20deg you lower the temp,you double the life of the trans.

as far as actual temp, i would start to worry when trans temp is higher than engine temp.
 
I just bought a temperature gauge for the transmission on my 97 k2500 suburban, where would the best place to install the sending unit? I have the cooler in the radiator as well as a factory air cooler behind the grille.
 
The best and most accurate place is in the output line, as close as you can get to the tranny. Pan temps is fluid that already went threw the cooler.
 
I'm using my programmer to detect temps. Not sure where the sensor is located bit after long hard uphill pulls in second gear at 4500 rpm my temp was around 170. Never got any higher. No check engine lights anymore either. The programmer and the WD hitch seemed to fix things.
 
I have a 98 toyota with 35s and and stock 4.10 gears and an auto. I installed a tranny temp guage and it stays around 180 but easily gets up to 210 in the summer in city driving. I have the stock cooler and an aftermarket external cooler and it still gets warm. What else can I do? do they make bigger tranny oil pan? maybe an additive?
 
I added a bottle of Lucas to my tranny in addition to the programmer. The combination of the two really seemed to help me. Add some Lucas and see what happens.
 
When I had the big block truck (4l80e) pan temps would run 140-160 deg empty on the highway, depending on ambient temps, . Hit ~180 around town. 210 on the big hills.

Ideally you'd monitor both pan and return line. But pan temp is whats about to go back into the trans. The 4l80e sensor is in the pressure sensor/plate and IMHO is a good averaged indicator of whats going on.


My van has a temp switch in the cooler to kick the fan on at 180. I can see when it comes on/off on the lighted switch. After driving the van enough I know what conditions it will come on by watching my engine temp gauge. While not precisely marked, it's easy to see trends. I also switched to Dex6 full synthetic.
 
Chris,
My apologies for the hijack :beer:

transman731 said:
the only product i use in my shop is www.lubegard.com if you go to automotive and click transmission
Click to expand...

Lee,
What are the benefits of running "lubeguard" in a GM auto? Specifically, a 4L80E with a 180K :D

yager said:
Ideally you'd monitor both pan and return line. But pan temp is whats about to go back into the trans. The 4l80e sensor is in the pressure sensor/plate and IMHO is a good averaged indicator of whats going on.
Click to expand...

Mike,
Did you run both sensors (pan & return)? Also, what did you use to monitor the 4L80E's TFT sensor?
 
dave - no not at the same time. Line port always was high and spiked on hills. And after reading it was normal as that was essentially converter temps. I only had one gauge so I hooked it up to the pan sensor when i added the hughes deep pan. I had considered putting a switch to the single gauge but never did.. BigJuggy has the truck now so maybe he will chime in.. I think it only hit 300 degs that one time ;)

There was another thread about the scan gauge. I'd like to get that setup at some point. Even thought I'm sorta watching return line temps via the light when it hits 180. It'd be nice to see more details.
 
Gotcha! Was thinking the BBC/black truck was TBI(?), so wondered how you were reading the 4L80E's TFT broadcast...

If nothing weird happens, I'll likely order the ScanGauge this weekend...
 
It was TBI, 1995 OBDI BUT had a PCM from 92/93 on even if a stand alone controller (diesels). 4l80e was still fully computer shifted. So it still had the internal trans fluid temp sensor (TFT), just limited logic for the PCM to do a lot with it.

Thought I never read it off the buss via the ALDL stream I've seen the referenced etc..
 
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