I have a 1999 superduty 7.3 diesel. When I'm haulin the tans over heats and the OD ON/OFF light flashes. Po1783 Trans got over 270 Degrees is code I get when I scan It. Anyways I'm putting in a temp gauge so I can keep an I on it. Where's the best place to put the sensor. Right now I have it T'd into the cooler line The hotter of the two I'm assuming the out going line But it doesn't seem to get very hot. When I'm moveing but when it sits and Idles after driving it goes up.

I kinda figured that I would do the gauge first so I can see how much differance a bigger trans. cooler actully makes. Anyone done this or have any input for me i'd appreciate the help.

I know the newer SD's come with a gauge allready (Lucky)

My experience is to put the sender in the cooler line leaving the transmission. This is typically torque converter temp as the fluid comes thru the coverter last before leaving the transmission. This is also the highest temp as the torque converter creates the most fluid temp. You can also mount the sender in the pan but the temp can be as much as 40 degrees less.

Thats what I mean by out going line. Going out from the trans. I'm going to run it for the weekend like this and see what it does. When I have my scanner plugged in it runs at about 225 is what it says for the trans. fluid temp. Thats when I'm being mean to it though. I'll probably pull something around this weekend and that is what I'm really interested to see.

225 is too hot. One thing you can check is the bypass tube. Sometimes when they get old they allow fluid to bypas the cooler even when hot. It's the black tube running from the front to rear cooler lines on the tranny.

I bypassed mine, even in winter it's not really needed here.

Get the biggest baddest stacked plate tranny cooler you can find and install it. Also, get that trans flushed completely and put new fluid in it. That stuff breaks down fast at those temps.

you have a 4R100 right? there is a small plug about half way up the body of the trans on the right side, it is the place to put the temp sensor. how do i know? i talked to Greg Evans, an engineer who designed it :)



also he has a tranny cooler for your truck. i have it.
i also have a Moroso fabbed trans pan that adds 4 :eek: quarts. it holds 21 quarts now :smokin:
he ALSO does valve bodys cheap.

factorytech.net. hes a real standup guy, i would buy from him again!

Need one of these, dropped my tranny temp 30 degrees on average in 2 different rigs. Don't even need the fan anymore. Look on the ford diesel sites, I forget the name of it right now.

http://ox.users.superford.org/GREEN_DILYSI/TRANS%20COOLER/STACKED%20PLATE%20INSTALL/DCP01685.JPG

Holy friggin' image. Way to mess up my page settings. :flipoff2:

I don't know about '99 or the 4100 but I know that if my tranny (E40D) temp hits 200*F, I have to flush it and refill it because that is the temp that the fluid breaks down at.....for what it is worth.

As I understand it... sump temp is what should be monitored... so a sender in the pan would be best. Most guys put the sender in the diagnostic port on the drivers side of the trans towards the front just above the pan, there is a small 1/8 npt plug there already. Apparently this is a passage between the sump and the pump. It's where I put my sender for my auto meter gauge and I see temps that are right in line with what others report.

I can't find the chart right now, but there is a ford chart that says the 4r100 can run at a sustained temp of 227*.

Personally I'd think about backin down before I let it get up that high. Highest I've seen was about 205* pulling pretty steep grades 7-10% and a very windy road to boot. The t/c was unlocked alot because of the slow speeds pulling out of corners. I was also running my edge box on the 55hp setting... which makes the trans heat up a lot quicker when the t/c is unlocked. I have a transgo tugger kit installed in the trans and it helps alot with shifting and temps. I also pay attention to whether the t/c is locked or not when pulling grades with a load... there is a drastic difference between the two! someday I'll get that t/c lock switch on... :rolleyes:

hey, get the moroso pan for it. it adds 4 quarts!!!!!!!!!

I'm going to move the Sender to the side of the case. Also I think maybe my cooler is plugged so I'll try to flush it out.

Thanks for the response I'll keep you posted

Ok I moved the sender to the side of the trans and now it reads about 10 degrees less than the scanner I can live with that. My cooler flush just showed up I'm going to try this and go for a good beat tonight and see if it stays cool or gets warm

Holy friggin' image. Way to mess up my page settings. :flipoff2:


Happy?? :flipoff2:

that plug on the side of the tranny is a easy spot to put it but i've talked to several tranny guys and they have said that there isn't much flow through there to get an accurate reading the best place is in the pan

It seems to be running cooler after I flushed the cooler it didn't look like it was blocked but I flushed it both ways I drove home and beat the $hit out of it the whole way about 25 miles 90+ mph on freeway plus stop and go at times it was at 175 degrees on the gauge and the scanner said the temp would be about 180 I'm going to keep checking though because I'm not satisfied that this was the problem.

For comparison, my tranny runs about 60-70 degrees above ambient temp when in OD, towing or not 50mph or 80. Around town for extended periods it will run 70-85 degrees above ambient empty.

Even in the mountains towing 8000 lbs it doesn't get much past 200 degrees and even then only when it's hot.

Buy a V10 cooler if you are worried. One of the diesel sites sells them as well. I think it has a 40,000 lb gvw rating.
http://www.dieselsite.com/index.asp?PageAction=VIEWCATS&Category=257

Also it still could be your bypass tube.
http://www.dieselsite.com/index.asp?PageAction=VIEWPROD&ProdID=172

I noticed you are in MN, I wouldn't bypass the bypass tube, helps the tranny warm up when cold. It's not an issue here, but I used to live in MN and I know it would give problems there in winter.

tranny temps are for fawkin pussy's. get a 6 spd

tranny temps are for fawkin pussy's. get a 6 spd

whatever homo :flipoff2:

There's guys out there with temp gauges on their 6 speeds too :flipoff2:

whatever homo :flipoff2:

There's guys out there with temp gauges on their 6 speeds too :flipoff2:


don't be all but hurt now. :flipoff2: