trans temp question

[timelessconstructionllc]

just installed transmission temperature gauge a few weeks ago. the first time i towed since the gauge install i noticed that my trans temps climbed from 180 (which seems to be where it runs at on a normal basis). but i was towing an 18 foot enclosed aluminum bumper pull with 4000 pounds in the trailer, all in all i was well under 7k lbs. My trans temp rose to 250. I have removed the check ball in the line and the temp sender is not causing any resistance within the line. Any suggestions?

 

[rscurtis]

Where are you measuring the temperature?

 

[JMDancoe]

rscurtis: Good question. I measure mine at the rear of my pan (deep pan) and have never gotten over 187. That was pulling 7100 lb travel trailer from Phoenix to South Fork, Co. over Wolf Creek Pass last summer. It was 106 air temp in Phoenix when we left. Usually my temp gauge (140 bottom figure) never even registers. Where do you measure yours?
___________________________________________________________________________
86 / 92 Retrofitted Cummins w/auto 2WD 246,000 miles - 96 Ram 1500 short bed 318 w/auto 4WD 307,000 miles - 2000 Jeep Grand Cherokee 4. 0 w/auto 4WD 160,000 miles

 

[NavyDood]

Wow. That is crazy especially with the mild outside temps you had yesterday. Like rscurtis asked, where are you reading the temps? What conditions were you in when the temp rose to 250°? Stop and go? Cruising down the highway?

My probe is in the out line. Towing 21K combined with the cruise set at 65mph in O. D. this past summer through AR and TX with outside temps at 106°F, my transmission was sitting right at 160°F.

 

[cerberusiam]

My trans temp rose to 250. I have removed the check ball in the line and the temp sender is not causing any resistance within the line. Any suggestions?

If that was in town which I assume that is where it was, you have a problem with the TC like we discussed.



Generally, in stop-n-go traffic in the summer if it breaks 220 you need a more cooling. It should not go much over that measured in the hot line.



If you are seeing 250 in the pan there is a major problem and the trans should have gone into limp mode and started banging shift points.

 

[timelessconstructionllc]

Measuring the temp in the hot line. I've noticed that if I sit with the truck in gear and my foot on the brake for two to three minutes the temp will rise and the od will turn off. This happened again yesterday evening. Cool weather, truck empty, driving city streets one block at a time, stopped for two min to talk to a buddy, went to take off and od was off and temp at 220.

 

[cerberusiam]

If the OD is shutting off the pan temp transducer is reading 240 or better, it is bad.



No way should your hot line be seeing 220 just idling in gear for a few minutes, even if the temp was 100 degrees.



Is the truck still wanting to pull thru the brakes at a stop?

 

[rscurtis]

As I've said in the past, to much disagreement, measuring the hot line temperature (by itself) is not a true indicator of transmission temperature. The oil supply temperature (in the pan) is a much better indicator of when you're overheating the transmission.

 

[cerberusiam]

The pan temp will ALWAYS be less than hot line temp. Does not get much more definitive than that.

 

[timelessconstructionllc]

On the hiway with the cruise set at 80 trans temp is consistently 150 degrees. Driving mile sections from zero up to about 55 MPH between each section it attendees 155 and 165

 

[cerberusiam]

On the hiway with the cruise set at 80 trans temp is consistently 150 degrees. Driving mile sections from zero up to about 55 MPH between each section it attendees 155 and 165

Is this after cleaning the thermostat or before?

 

[timelessconstructionllc]

After. However. , this very well could've been the case before cleaning the thermostat and I'm inclined to suspect it probably was. Especially since the temp still conditions when sitting at a stop with truck in gear

 

[cerberusiam]

Is the temp still jumping up at a stop in gear?

 

[timelessconstructionllc]

It doesn't jump up. Just slowly rises. But yes it's still doing it. P. S. sorry that some of my posts don't make sense. Damn predictive text.

 

[Prairie Dog]

I remember talking to DTT about a rebuild on my old Dodge and they told me that if I used their most efficient torque converter, I would have to put in neutral at every stop or the drag would be so bad that it would heat up and try to crawl forward. Could that be the issue?

 

[timelessconstructionllc]

It absolutely could. Cause when I put the truck in gear it gets up the brake pretty hard. But I don't know any of the things like what you are telling me BC DTT didn't tell me squat unless I. asked. its a good thing that I asked about what type of fluid just to. double. check. BC I had already bought a case of atf+4 then found out they wanted me to use Dex/merc. I never got a build sheet for my transmission or anything

 

[timelessconstructionllc]

Sorry. Last post was supposed to say. Gets up into the brake. As in pushes hard against the brake.

 

[cerberusiam]

If it gets up into the brake hard stopped the the temp is going to rise. There is simply no way around that. The tighter fluid coupling is going to heat the fluid faster in slow conditions. On the positive side the efficiency is much higher and you are transfering more power so you get to speed faster.



The answer lies in whether thats how the TC was designed, or, there is an issue with it. Hard to tell if you don't exactly how the TC was built.



I would have to question using the Dex\Merc if the temps are going that high. ATF+4 is much better at handling heat than most fluids.