Engine/Transmission (1998.5 - 2002) transmission temps

[BroncoMarc]

I installed guages yesterday and my transmission temp is looking way too high. Driving around city streets it gets over 250. I thought it might run cooler on the highway since the torque converter would be locked up and the cooler would be getting more air, but it still got up to just below 250. That was runing empty at a steady 65-70mph and 60 degrees outside.



This is making me worry alot because that was empty and the reason I have this truck it to pull my Bronco around which is about 7000 pounds including the trailer.



I've got the sender installed in the pan (from the advice of Genos) with a B&M plug kit. It's on the back of the pan toward the drivers side if that makes any difference.



When I put the gauge in I drained the fluid which looked pretty dark and maybe slightly burnt. Not too much very fine metal stuck to the magnet. I don't know if it's ever been changed (113,000 miles) since I've only had the truck for a year. I didn't see the remains of any gaskets other than the one I took off. I also put a new filter in and 5 qts of ATF+3.



Any sugestions? Am I going to burn this this up running like this? transmission seems to operate normally.

 

[KKaiser]

Sounds hot to me. Last weekend I towed my 8000 lb trailer over the Sierra with chains required. Second gear for fifty miles (no lock up). Max temp was 190 maybe 195. As soon as the chains came off the next 400 miles, at illegal speeds I might add, temp never went past 160.



Kent

 

[DavidC]

Is it he correct sensor for the guage? If so your way to hot for a reading in the pan. The brownish color confirms this. Unfortunately I went through the same thing and once it started it was all downhill (to a DTT upgrade ). When they get hot the first thing to go is the seals which creates internal leakage and lower pressures which eventually causes clutch slippage and valve body malfunctions. I would start saving the money for the inevitable. Sorry for the bad news.



Dave

 

[Snow man]

Id double check the guage,once it reads 140 in the pan,go try to touch the pan,you should be able to touch it for about 2 seconds before you cant stand it. if its col,or just warm,lthe sender is bad. I have a handheld lazer thermomter,just point it at the area you want to know,and it gives you the instant temp of it. In lockup on the highway,the pan should be under 160,IMO. My truck only runs 125-140 hot line in lockup.

 

[BroncoMarc]

I'm hoping it's a bad sender. It's an autometer phantom gauge from Genos, and it came with the sender. There was a tag on the sender post of the gauge warning not to mix up positive and the sender wire or it would damage the sender. I don't think I did that, but I did have power turned on as I was hooking it up. Also, the switched source I was using ended up being milivolts when everything was hooked up, so I had to find a different source of power.



Also, I don't know what happened to the wire that came with the gauge (if it did come with one) so I just made up my own wire. I'm guessing there wasn't anything special about the wire that came with it.



I'll try touching the pan after it's been warmed up. . see if I can burn myself. .



__________________

- Marc Reiter

1998. 5 Dodge Ram Cummins Turbo Diesel - BHAF, more to come...

http://www.broncomarc.com/ram/

 

[BroncoMarc]

ok. . I just ran it until the gauge got up to 240. I could hold my hand on the transmission pan for about 10 seconds. Anyone know what the conversion to farenheit is??



__________________

- Marc Reiter

1998. 5 Dodge Ram Cummins Turbo Diesel - BHAF, gauges, more to come...

http://www.broncomarc.com/ram/

 

[KKaiser]

Sounds like a bad something, thank God! Much better to have a bad gauge/sensor than a transmission running that hot. Good luck with your diagnostics!



KK

 

[tractorface]

Where did you wire the gauges "ground" terminal to. If you used a battery ground instead of a body ground, that could be your problem. Try using a hose clamp to temporarily attach a Ground wire to the body of your sender and terminate the other end on your gauges ground terminal. This will eliminate any false readings due to ground wiring.



How do I know this. ... . I spent a week chasing the same problem one that I caused. Had the EXACT same systems you are writing about. Final solution was to use an electrical ground clamp from the sender line to the Gauges ground terminal. Overkill but it works.



250 is Hot to the touch you would know if it was that hot.

 

[BroncoMarc]

I've got all the grounds (transmission, pyro, 3 lights) tied together and 1 wire running to a screw that goes in the dash that holds to metal pieces together. Everything else seems to be grounded ok. . pyro works great and all lights.



__________________

- Marc Reiter

1998. 5 Dodge Ram Cummins Turbo Diesel - BHAF, gauges, more to come...

http://www.broncomarc.com/ram/

 

[tractorface]

I think the one wire going to the dash is your problem. Try running the temperature gauge ground terminal out by itself. The ground terminal on the temperature gauge is really the "return" for the sender. The gauge is just reading the resistance of the sender. I posted the typical resistance values for the autometer sender at different temps on my earlier post in the 911 section. Checking the resistance directly at the sender with a multi meter will confirm that the sender is or isn't working properly.



The thread was titled "Good trans gone bad?" and is located in the 911 archive. pretty recent too. I got the sender information from Geno's. Sorry, not sure how to copy the link. my attempt is below



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=69994

 

[BroncoMarc]

PROBLEM SOLVED!!



THANK YOU TRACTORFACE !!



I just took a drive and it went up over 250 pretty quick. I got home, took the wire off the sender and measured the resistance at 400 ohms. According to your chart that should put it around 145 degrees.



Great. . I've got a good sender. . It must be the ground I'm sharing with all the other gauges. So, next I was going to cut the ground wire off from the rest and connect it to my cig lighter to check it. I started pulling the wire and. . hmm there's the end. . not hooked up to anything!



I hooked the ground wire up where I originally intended and the gauge dropped down to 140.



Thanks guys. .



__________________

- Marc Reiter

1998. 5 Dodge Ram Cummins Turbo Diesel - BHAF, gauges, more to come...

http://www.broncomarc.com/ram/